Why do you chill?

[FarmerTy]

For those who chill, what are your reasons for chilling?

Is it for purposes of not allowing the tank to reach a certain critical temperature? Like for insurance purposes... akin to why I keep a heater on throughout the year?

Or do you chill to keep a specific temperature... say 78 degrees? Perhaps you keep the house at a pretty high temp, therefore needing a chiller? Or is your sump in your garage and you chill to keep the tank temperatures from being 110 degrees in the summer. Or your AC went out like at Wizards place.

Just curious as I have never had a chiller. I actually keep my tank around 82-83 on purpose to increase metabolic rate and to keep it somewhat near the temperatures of where most of my coral are indigenous to.

“The most rapid growth of most corals is generally around 27°C to 29°C (80.6°F to 84.2°F) (Barnes et al., 1995; Clausen and Roth, 1975; Weber and White 1976; Coles and Jokiel, 1977, 1978; Highsmith, 1979a, b; Highsmith, et al., 1983).

Again, just curious, trying to see viewpoints on the "other side" and see if I'm missing out on something. Thanks.

-Ty

[wizardx322]

i chill cuz my a/c out right now lol

[George Monnat Jr]

i chill cuz my a/c out right now lol

There's no way my wife would let me cool the fish before her and the dogs.

[mFrame]

Most people chill because they run MH lights in a canopy and evaporative cooling can't keep the tank from heating up too much.

[DerrickH]

I chill because I think my pump is nuclear powered. 1500gph pump puts out a lot of heat and I have it ran externally! Even with LED lights my temps will hit 82f if I dont use a chiller. Ive always ran my tanks in the 77-78 range. Then again, Ive never really had much sps. Does SPS do better in warmer waters? The global data chart in my apex says the water is a lot colder than I though it would be...

[Timfish]

I use chillers to deal with the heat issues when ac temp is turned up or off on the weekends in offices. I generally don't bother with chillers, in many situations fans are able to do quite a bit of cooling with less noise, no additional plumbing, less heat (a 1/3 hp chiller is producing roughly 250 additional watts), easier wiring, lots cheaper the caveat being there is a lot more evaporation.

While I don't dispute the temperature range at which the fastest coral growth is achieved I seriously doubt that temerature range is found consistently throughout the tropics. Nilsen and Fossa (The Modern Coral Reef Aquarium, Vol 1 pg 214) point out at temperatures above 30 celsius there is inceased risk to the cells transport systems neeeded for photosynthesis. Over the years heat is consistantly causing problems and I'm a lot more comfortable with keeping a tank at 78 and having some safety margin than keeping a tank at 84 and having only to go one or two degrees more to start causing issues. I am also hesitant to accept the premise that it's healthier for the corals to keep them growing at thier maximum growth rate than at a slower growth rate.

I would also point out we are dealing with many different species and varities. One person's experience with the "corals" in thier tank may not translate to another person's "coral" tank with a different set of species.

[wizardx322]

i chill cuz my a/c out right now lol

There's no way my wife would let me cool the fish before her and the dogs.

lol i got a window ac in my room

[FarmerTy]

Derrick, see the article at the link below:

http://www.ronshimek.com/salinity_temperature.html

Timfish, this is the type of discussion I like. Thanks for pointing another article of interest to read. I will have to get a copy of that.

With increased risk of to cell transport systems for photosynthesis at 86 degrees Fahrenheit... and according to the linked Shimek article, relatively little coral species persist at a temperature below 75 degrees Fahrenheit, we should all be leaving our tanks at 80 degrees Fahrenheit! haha. Again, Timfish is correct that we are dealing with different species and varieties. For me, keeping a majority of SPS, optimal temperature for most SPS being around 84-86 for growth and health, I keep my tank at 82-83 degrees Fahrenheit and everything is great.

For others, other factors such as increased algae growth or decreased oxygen levels may play more of a factor (skimmer will help with that). I don't by any means recommend everyone run at 82 degrees Fahrenheit. Just works for my system and the species of coral I keep. That leaves me a little less margin of error when it comes to overheating but 9 years of reefing without a chiller has left me okay with that. And the 1 out of 3 times I overheated, it killed all the horrible xenia in my tank that was everywhere I didn't want it to be. So, boon for me! haha! The other 3 times though I did lose a couple of species (1 chalice frag, all of my hammers, really cool favite, and one fish... rest in peace Fido).

[offroadodge]

lets me see...I chill because of lighting heat. 1350Ws of light over a 5'x30" area. I keep mine at 80 degrees year round. In the summer it runs 80-80.6 and winter it runs 79.3-80. I tried not to have a chiller but theres just to much light over my tank. I went over kill on my chiller (1.5hp) but in the event of a disaster of not having A/C during a 100+ degree day i just wanted to know i would NEVER have and issue.

[JasonJones]

One of my favorite discussions on aquariums temperatures. By Mr. WIlson on RC. The original post is buried somewhere in a 300 page thread on RC, but this particular article is housed on the RC thread owners site: http://petersfishtank.com/best-practices/

Mr.Wilson Writes About Temperature & Climate Control

First of all the reports that reef tanks thrive at 82°F are absolutely true. Most SPS (small-polyped scleractinian corals) do best at 84-86°F. I aim for 80°F because it is the easiest value to maintain without using any additional resources/energy (heaters & chillers). Once you plug in all of your equipment, the tank will level off to about 79-80°F. It would require the use of one or likely more heaters to maintain 82°F, so I go with the flow and settle with an easily manageable 80°F. If you have a chiller, it should be set to come on at 84°F as basically a fail-safe. Heaters should bet set to come on at 79°F to maintain consistency. If you set your system operating level to 82°F, it leaves a little less room for temperature climbs. A target temp of 80°F leaves room in both directions for error.

A friend of mine was in Indonesia recently and he reports that the maricultured (ocean farmed) SPS are in 90°F water. Coral growth ceases at 76°F, so 77°F is at the bottom margin of their range. 93°F is the top of their range, so 84-86°F (low/high) is somewhere in the middle. 84°F is also the reported level for best growth/health.

I haven’t found “excessive coral spawning” to be a problem. If it was, it’s the kind of “problem” I want.

I believe the data Shimek uses in the article is from 1995. The seas have warmed in the past 15 years.

You need to establish where your temp will tend to drift. Most people have a temp that drifts up during the day while the lights are on. For this reason, it is safer to keep the temp below the optimum 84°F and keep it at 82°F. It’s easy to fix a temp that tends to drift down with a heater, so it’s not necessary to keep it higher than the optimal 84°F.

We aren’t keeping corals from the Atlantic Ocean or Caribbean Sea so the average temperatures from there aren’t accurate for our South Pacific, Australian and Indo-Pacific corals. I’ll look it up when I get the chance, but I doubt the temperatures where our corals come from go below 80°F. This article explains the difference between water and coral temperature.

There are a few things to keep in mind when deciding your optimum temperature. As I mentioned earlier, you don’t want to sit at the margin of the safety zone. Find a spot in the middle where you have room for error minor temperature swings. Temperature drops at the bottom of the safe margin are more dangerous than increases at the top of the margin.

The other issue to take into consideration is your corals need to have all of their needs fulfilled before you raise the temperature (or any parameter for that matter) to the natural optimum level. You can compare it to what a healthy diet for an athlete would be compared to an aquarium designer who chats on a forum all day I certainly have no business consuming the caloric intake of a marathon runner. Corals must have adequate light, carbon source, nutrient levels, major and minor salts and temperature. In the wild, corals will grow best at 84°F, but this isn’t necessarily the experience an aquarist will find in their tank, particularly if they cannot maintain dissolved oxygen rates near saturation levels. Warm water holds less oxygen, so good flow volume and dynamics are vital.

The Shimek article pretty much covers any questions. He claims keeping corals at the low end of tolerance is a common mistake. Calcification ceases at the low end so running chillers to maintain unsafe levels is a poor practice. If/when those chillers fail, you lose stability and increase stress as the water heats up. If your tank naturally runs at 81-82°F with no heater or chiller running, why expend unnecessary resources to lower it if growth and health is better at 84°F?

From Shimek’s article:

“in reality relatively few coral species persist at temperatures much below 24°C (75.2°F)”

“The most rapid growth of most corals is generally around 27°C to 29°C (80.6°F to 84.2°F) (Barnes et al., 1995; Clausen and Roth, 1975; Weber and White 1976; Coles and Jokiel, 1977, 1978; Highsmith, 1979a, b; Highsmith, et al., 1983).”

“the no growth lower limit of zero calcification occurred at 23.7°C (74.7°F) in corals from the Gulf of Mexico and at 25.5°C (77.9°F) in corals from the Caribbean Sea.”

“The most diverse coral reefs are found in a band running from New Guinea and Northern Australia in the west to Palau in the Western Caroline Islands up through the Philippines and Indonesia in the east (Veron, 1986). In this area, prior to the recent period of global warming, the atoll water temperature averaged around 84°F and probably never got as low as 80°F.”

“At 10°C below the optimal temperature, the metabolic rate would be reduced by about 96%, or put another way, it would only be 4% of normal. Under these sorts of conditions most animals die. In fact, most organisms will die if maintained for extended periods under conditions that constrain their metabolic rate to one half of normal. Even metabolic rate reductions to about 75% of optimal may cause significant problems or death (Withers, 1992). A reduction of this magnitude will be caused by keeping an animal with an optimum of about 82°F at a temperature of about 77°F.”

“Both the temperature and salinity of many reef aquaria are kept near or even somewhat below the lower normal survival limit of physiological tolerance for many of the common animals. This results in substantial and unnecessary mortality. In effect, these mini-reef systems keep the animals just healthy enough that they die slowly.” – Dr. Ronald Shimek

We’re talking about a variety of variables that all intertwine. If the question is “What temperature should I keep the coral at?”, then the answer is 84°F. If the question is, “What temperature should I keep my tank at?”, then the answer may differ.

It’s possible that more nuisance algae would grow at a higher temperature. It’s also possible that there is less dissolved oxygen, but I think the difference between 76°F and 84°F is negligible with regard to oxygen saturation. My point about flow rates earlier was simply a warning that if you have a problematic tank with inadequate flow then you don’t have room for higher temps.

Fish are more active at a higher temp. They eat more and grow faster. They would not have a problem at 84°F as this is what they experience in their natural habitat.

The point that Ronald Shimek is making is that it is foolish to keep the temperature at the absolute bottom of the safety zone.

For a large system like Peter’s, I would use an in-line titanium heater run on the main controller. Sump heaters tend to degrade due to salt exposure in the seals and wiring. They also take a bit of a beating during water changes and servicing as they are left on while exposed to air. I use a piece of styrofoam to make a float for the top of the heater so it can float in the sump, keeping the sensitive parts dry (suction cups don’t last long in salt water). The heater(s) should be located in a part of the sump where the water level is constant. The styrofoam floats will allow the heater to follow the water level, should it fluctuate. I would focus my attention on climate control of the ambient room temp with air conditioning or a furnace/boiler, and save aquarium devices in-line or in the sump for fine tuning.

While I would never talk anyone out of a fail-safe device, you have to remember that everything you plumb into your system could potentially leak, and everything you plug in could potentially cause stray current or shock/fire hazard. I don’t use chillers as a general rule. It’s part of the K.I.S.S. (keep it simple stupid) or “less is more” approach.

The factors that influence system temperature are as follows…

1) Ambient room temperature: North American homes are warm in the winter and cool in the summer, thanks to our desire for convenience and comfort and with a little help from huge utility bills As a matter of fact, many homes are warmer in the winter than they are in the summer, and cooler in the summer than in the winter. Typical ambient room temperature is somewhere around 72°F (for the record, we use metric in Canada).

Working with 72°F, we can assume that still water will reach equilibrium with that temperature. Once you start moving the water it has more contact with the surface where the temperature reaches equilibrium. A cooling effect starts when surface water evaporates and takes with it heat. Evaporative cooling is a very important process that we will discuss later.

2) Aquarium location: This factor is directly related to the ambient room temperature covered above. An aquarium located in a basement, or with a sump in the basement or garage will run cooler than an aquarium in an upper floor of a house. Even the position of the tank with relation to the floor makes a difference. While I operated a tropical fish wholesale warehouse, I found that the three levels of tanks showed different temperatures. The freshwater tanks where not on an open system, just air-driven sponge filters. I heated the warehouse to 80°F, but the bottom tanks 1′ off of the ground were 74°F, the middle row 3′ off of the ground were 76°F, and the top row 5′ off of the ground were 78°F. Peter’s radiant floor heating will eliminate this heat gradient issue. Placing the sump directly on a concrete floor will offer cooling.

3) System volume: Having a large sump is a cheap and easy way to improve thermal dynamics if you have the space. The extra system volume will also improve water quality, as the saying goes, “The only solution to pollution is dilution”. The best solution is actually filtration, rather than sweeping the problem under the rug, but it doesn’t rhyme so I doubt it will ever catch on.

Saltwater has greater density than freshwater, so it holds its temperature longer. Large tanks (over 200 gallons) are particularly stable with little or no fluctuation caused by day/night ambient room temperature shifts. In other words, the room may be cooler at night, but the tank will stabilize at a compromise temp somewhere between the day and night temp. The large thermal mass of a big tank makes quick temperature changes up or down more difficult, but nature doesn’t like change, so overall the thermal mass is a good thing for stability. Remember that bleaching incidents on natural coral reefs has been noted after only 2°F temperature increases. This doesn’t mean a 2°F increase in temperature will bleach (expelling symbiotic algae/zooxanthellae) or kill corals, but it does underscore the necessity for stability.

4) Heat transfer: Every electrical device, including chillers add heat to aquariums. Add a few degrees for pumps, a few more for UV sterilizers and a lot more for lighting and your cooler than room temp tank is suddenly 10°F hotter. Some of this heat is unavoidable, but most of it can be at least minimized. Directing a 12 inch circulation fan perpendicular toward the display or sump surface will drop the temp 5-9°F. The evaporative cooling effect will tax your top-off system a little more so make sure you can keep up with the demand. A second fan can be used to blow across the surface of the water, pushing radiant heat from the light away from the water. Raising or lowering the lights will also influence heat transfer.

Venting the cabinet or filter room is an often overlooked detail of climate control. Some pumps don’t employ cooling fans and subsequently run at very high temps (130-140°F). This is not a problem if the heat is allowed to vent away from the system, rather than trapping it and raising the ambient temp and surface water temp. Chillers are an important device to vent as the heat exchanger will dump that heat right back into your system so it works against itself.

5) Water movement: As mentioned in the previous points, good water movement will increase the amount of water exposed to the surface for thermal and gas exchange. A good system of flow dynamics assures that water is moved from the bottom where it is cooler and lower in dissolved oxygen to the surface where it can be oxygenated and heat can vent. Using a glass top will raise the temperature about 5°F. While this is rarely desirable, it’s a good practice if there is an extended power outage and your back-up power is limited. I assume Peter has a natural gas generator and UPS/deep charge marine battery backup. Certain filtration devices (gas reactor, wet/dry filter, shallow ATS etc.) work as evaporative coolers or cooling towers. In general, these evaporative efforts are directly connected to improved gas exchange as well.

6) Air quality: Fresh, dry air will be cooler than stale humid air and gas exchange is more efficient. Peter’s HRV unit is more than enough to handle this issue. It also vents equipment to deal with heat transfer.

You should have a bypass line on all of the equipment such as the chiller so it can be taken offline for service without affecting the operation of the aquarium. There should also be a true union shut off valve on each bulkhead of the display tank. This way you can fill and run the tank independent of the plumbing and filtration devices and if your plumbing springs a leak it can be repaired without draining the tank or capping the internal plumbing.

There’s a handy chart on this site that illustrates the relation of salinity and temperature to dissolved oxygen potential.

For Peter’s tank I recommend he pick up two 1000 watt titanium probe heaters and plug them into a controller. Make sure the module/power bar can handle the 20 amps that it will draw. Having each heater run on a separate controller will resolve this issue and act as a failsafe. If the controller jams in the on position the tank will only go up 5°F instead of 10. If the controller jams in the off position, the other heater is still on the job.

We discussed heaters earlier in the thread. The experts agree that the ideal temperature is 86°F. The room temp may drop at night even with your climate control system. The most important issue is stability. In my experience the tank will run about 5°F warmer than the room. Evaporative cooling will drive the temp below room temp and LED or well vented MHL lighting has little affect on water temp. Your pumps are all external so they won’t transfer as much heat as submersibles. Your UV unit will add a bit. The trickle/wet dry filter will cool the water through evaporation and contact with air.

Where you see a lot of overheating issues is with a tank under 200 gallons with MHL lighting crammed into a tight canopy, poor cabinet venting, inefficient pumps, powerheads, and high ambient room temp.

Cold air drops so your basement will have a cool ambient room temp year round. Your remote sump and equipment will keep the tank cool. I think you said your live rock vats were about 78°F.

The problem with magic numbers is they aren’t magic for everyone. Peter has a high tech climate control system and a budget to keep it where he wants it. There are numerous fail safes and the high water volume and acrylic tank tank construction offers yet more stability. Fear of a temperature drop during a power outage or a high temp spike during a heat wave are not factored in when establishing target temp. If you have all of your ducks in a row, then a magic number of 82-84°F fits the bill (no pun intended).

If you feel you are at risk of power outage, extreme weather (hot or cold), or equipment malfunction, then you should aim lower, closer to the middle of the temperature range (79-80°F).

In most homes, it gets cooler at night. This can drop the system water a few degrees, especially since lighting and in some cases pumps are off at night and cooling fans are often left on. Most fish and corals are from areas with stable temperatures. The temperature swing is more injurious than the temperature value itself. For this reason, it makes more sense to keep the heater at 80°F rather than 79°F or lower so nightly drops are compensated for.

You can use a chiller to keep the temperature from rising over 80°F, but that represents a $1000 – $1500 equipment cost and elevated operational costs. It also increase the possibility of leaks and equipment failure.

I don’t know the actual numbers, but the amount of dissolved oxygen in 79°F water versus 82°F water isn’t a huge difference. Keeping the resting temperature lower will add extra minutes of air, rather than hours.

I posted an article by Dana Riddle earlier where he compares water temperatures to actual coral temps in aquaria. He uses a directional infrared thermometer to test the temperature of the coral. Some lighting systems emit radiant heat that reaches the corals, making them warmer than the surrounding water. The sun also generates radiant heat, obviously, so this heat transfer is not unique to our aquariums.

[mFrame]

One of my favorite discussions on aquariums temperatures. By Mr. WIlson on RC.

Mr.Wilson Writes About Temperature & Climate Control

....

Credit where credit is due, for informative articles like this let's link back to the source site and thread. You can duplicate portions here for the sake of conversation but I want the original source to get the google and the credit for it.

[Niko's Reef]

Wow. I love ARC. I have learned so much on here in the month that I have became a member. I haven't been into coral until lately. I always thought 78% was the magical # for a saltwater tank. My corals have made it, but a few haven't fully bloomed. I have my heaters in the sump. Looks like I will be adding an additional heater to the main tank tonight. Will gradually bring the heat up. Really informative. Thanks. Niko.

[+o0zarkawater]

I don't chill, I just hang out.

Over the past 2 summers my tank has easily reached 84 degrees on a daily basis with my previous T5HO lighting. I never lost any corals or fish, nor saw any signs of stress. I'm curious to see how we do this summer with MH lights.

Great articles guys.

[FarmerTy]

Wow, Mr. Wilson goes into great detail about the rationale for how you should decide on an optimal temperature for your tank and Shimek's research. I only read the Shimek article. Great add on Mr. Wilson, you can google his link as he has a lot more discussions as well about other reef topics.

Niko, I would look specifically on what temperature you should keep your tank. I think you said your tank is newer?

Reason being is I don't want everyone to just take this information as a blanket statement that everyone needs to put their tank at 82 degrees.

I do it for my SPS, I do it because I have an oversized skimmer that adequately aerates the water, I do it because even though it encourages green algae growth, I have biopellets and tangs that keep it at bay, I do it because average temperature in the room is 78 degrees, I do it because I have 3 metal halides with a small clip-on fan on the side and an auto topoff system to compensate for the evaporation, I do it because I have my own do/ri water to easily refill my topoff.

If I mainly had softies or LPS, I would not run the higher temperature, no point in my mind and all that risk of overheating for nothing. I wouldn't run it if I don't have the eye for seeing changes in my coral and knowing immediately that there is something wrong, or that my tank is not mature yet (at least 1 year in my opinion). If I didn't have an oversized skimmer, I would not run the higher temperatures... I hope you get my drift. Each tank and application is different. Sorry, not singling you out but I just want to make sure everyone is not jumping on the bandwagon without fully thinking about their own system charcteristics and the need for it or not. Plus, why expend the extra money on heating your tank during the year for no benefit if zoas or LPS are happy with 78? Just my 2 cents.

[JasonJones]

One of my favorite discussions on aquariums temperatures. By Mr. WIlson on RC.

Mr.Wilson Writes About Temperature & Climate Control

....

Credit where credit is due, for informative articles like this let's link back to the source site and thread. You can duplicate portions here for the sake of conversation but I want the original source to get the google and the credit for it.

You got it. Link added.

[DerrickH]

I will try increasing my temps on my chiller slowly. .2f at a time over a week and see what happens. Ive got a green milli that browned out due to high nutrient content and low photo period(cyano exploded). Very interesting info.

[Timfish]

I have not yet taken the time to read through all the other links that have been posted. Reading through the posts one thing I wanted to point out is there is a very big difference between sexually propogating corals in a tank and asexual propogation like fraging. Part of Delbeek and Sprung's argument for keeping reef aquariums between 23-25 °C (74-78 °F) with a high of 27 °C (80 °F) ("The Reef Aquarium" ch 4) is to reduce the risk of sexual propogation and the huge release of nutrients this would dump all at once in a system. Arguably this is a moot issue, I myself have only had this happen once to the best of my knowledge but it looked like about half a package of cyclopese was dumped in the tank and this was just from a large colony of stone polyps. It goes without saying what could happen if all the corals coordinated thier spawning.

More to the point they document bleaching events in Fiji and the Birch Aquarium at Scripps in San Diego where corals were fine at 28 °C (82 °F) but bleaching started to occur at 29 °C (84 °F). The Birch Aquarium was more specific with signs of bleaching starting to occur when the temperature stayed at 28.9 to 29.4 for ten days or longer.

Delbeek and Sprung also point that while for one study the maximium calcification rate for Galaxia and Dendrophyllia is at 25 °C (77 °F) other studies show the temperature at which maximum calcification occurs varies on the local normal temperature. I am curious to read the research in some of the other links that have been posted but as Delbeek and Sprung have pointed out the temperature at which the coral has been acclimated to needs to be taken into consideration.

My own experience tells me 74 to 78 °F is safer but it's not that big a deal. I don't start having issues until tanks get around 84 to 85 and have had tanks at 88 for short periods without problems and probably have had tanks go above 90 for at least a few hours with very minimal loss. Below is a jpg of a 500 gallon that has 7 250 watt HQI bulbs, is in an enclosed cabinet and does not have a chiller and is cooled with fans pulling in outside air and venting to the outside (with cabinet doors closed there is essentially no air exchange with the air conditioned air of the office). Normal seasonal temperatures are 72 °F in the winter and 84 °F in the summer (this is the tank that sometimes hits 88 °F). The 2 large Green Slimmer colonies were 1" frags in Jan/Feb '09. The pink Birdsnest in the upper right corner is a frag off the one that can barely be seen between the 2 Green Slimmer (along with red monti, a brain and A. millipora colonies) that itself was a 2" frag in summer of '09. The birdsnest partially bleached winter last year (Jan/Feb '11, lost some of the brown zooxanthellae, I suspect the temperature dropped below 71 but I never saw thermometer read below 71.8 °F) but did not bleach the year before ('10) or this year. Clearly good coral growth can be maintanied even with relatively large temperature swings.

[Niko's Reef]

Jeeper Ty,

No problem on the singling out. I actually like it, because I'm not sure and new to corals. I'm just a student willing to be taught the ropes. It provides me more insight and could stop me from doing something foolish. Sometimes the tank has dipped to 75. I like it cold in the house and the AC is always on full blast. During the winter, I never turn the heater on either. Never allow the house to get over 72, and don't care what it dips to. People call it an ice box. You are right, my tank is new. It's only 4 months old. It's just that 2 of my Zoa's and a SPS aren't opening/blooming fully. 1 of them is the King Midus that I got from you. It was doing great until the middle of last week. All of our water parameteres were the same, so I thought that the temperature might be an answer after reading this post. Nothing has changed with the water parameters, and all the other corals are doing great. I do have an oversized skimmer, but I don't have any biopellets, Tangs, or algae eaters besides clean up crews to keep it at bay. Haven't experienced any problems with algae thus far. I do understand how the increase in temperature could increase the algae. I don't have a do/ri system, because I have a machine down the street from me. I’m thinking that I should invest in 1 though for saving $. Sounds like the issue could be that the tank just isn't matured enough for those few corals. Got a few things to consider.

Thanks a Ton,

Niko

[Viet-tin]

I chill because my tank sits in my garage through the wall and in the summer water at 90+ kills everything...

[Niko's Reef]

I decided to go ahead and push the temp up. Right now I'm at 79. Shooting for 80. Both of the Zoa's are opening up, so lets hope I found the right temp. Niko.

[FarmerTy]

Also another thing to think about Niko is flow. Zoas are so finicky and we all make the mistake of treating them all the same, even though I'm sure they are collected from multiple different areas of the reef. My King Midas loved medium flow and a lot of light. They were also the most picky out of all of my zoas and are the first to close up when they don't like something.

[jestep]

With a single fan on my rimless, I've actually needed to use a heater to maintain the temp which is dead stable at 78. In my JBJ it was a struggle to keep it below 82 in the summer. With that being said, I had mine hit 88-90 for about 6 hours as a result of accidentally turning the fan off, and it resulted in the death of about half my coral at the time. If for nothing other than a buffer, I would trend towards the lower end of the suggested range. Also, a max temp is meaningless if the temp suddenly spikes. If I were to increase to the 80's again, I would definitely do it over the course of several weeks to prevent bleaching or necrosis. So many times I see people trying to adjust their params to get some specific target, but stability is what really matters as it's in some acceptable range. This goes for fresh as well as salt water. You can keep a discus in the hardest water on earth, as long as it stays that way before during and after water changes and daily light changes.

[Sherita]

I chill because I live in a very old farm house with no central heat or air. It's not unusual to see 30 degree temp swings every day. A good chiller/heater combo helps keep my tanks from cooking or freezing.

[+dapettit]

My wife keeps the house at 80. I'm constantly lowering the temperature to 78. I have 3 - Wal-Mart fans on my tank controlled by my AC3. Fans come on when the tank is at 78.5 and off at 78. If the tank gets to 81 the controller turns off MH1 then back on at 78. If the tank gets to 81.5 both MH are turn off until the tank reaches 78, then back on. The fans continue to run as well. The tank has only gotten up t0 81.

I have a lot of evaporation but I'm a Florida boy so it don't bother me. A chiller would be nice but not necessary for my "current" situation.

Like I always say, it may work for me but not you or it may work for you and not me. . . I love this hobby!

Dave-

[FarmerTy]

80! I'd melt in your house Dave! Ideally when I get my controller, I would like to use the combo of a heater and fans to keep my temperature more stable but I'll just say my corals are acclimated to the daily fluctuations and everything is happy now. Ignorance is bliss.