[email protected] Posted January 13, 2010 Share Posted January 13, 2010 I'm down sizing my reef tank from my 175G bowfront to a 72G bowfront (keeping the 175G as a fish only tank). My 175G has 3 x 250w MH retrofits on it. I was thinking of moving 2 of them to the 72G but wasn't sure if that would make the water run too hot without a chiller. I've had a 72G before and was running 2x175w MHs without a chiller by keeping the top off and adding some small fans. Anyone has a setup similar to this? Quote Link to comment Share on other sites More sharing options...
+Hydro Posted January 13, 2010 Share Posted January 13, 2010 yes it would get to hot without a chiller, I can only run one 250 over my 72 gallon bow front without a chiller and even then the water gets to 81-82 degrees. This is without fans though. Quote Link to comment Share on other sites More sharing options...
[email protected] Posted January 13, 2010 Author Share Posted January 13, 2010 Hydro, How do you have your 250W placed? is it centered? and doesn't the center brace at the top of the tank block some of the light that way? Do you have the glass top and hood cover off? Quote Link to comment Share on other sites More sharing options...
offroadodge Posted January 13, 2010 Share Posted January 13, 2010 if you had fans blowing at the bulbs you could get away with it i think if the house temp stayed at 75-77. Or i have a chiller forsale cheap, 6 months old bought from Marine Depot in Aug2009. Its the JBJ 1/10 titanium with a pump. LMK Quote Link to comment Share on other sites More sharing options...
+Daniel Posted January 13, 2010 Share Posted January 13, 2010 I had 2x250w on my 90g. My chiller ran very minimally, but then again, I kept my temp between 78.5-81.5 w/ 77 degree ambient with two fans blowing across the bulbs. Quote Link to comment Share on other sites More sharing options...
Gonzobob Posted January 13, 2010 Share Posted January 13, 2010 With proper airflow you should be fine. I have a 250 on my 34g Solana. I do run a fan on the sump chamber and on the fixture while the light is on and have no issues Quote Link to comment Share on other sites More sharing options...
+mcallahan Posted January 13, 2010 Share Posted January 13, 2010 Good Lord Hydro...I have 2x250W over my 90G and my temp swings from 77.4-78.3 during the summer. In the winter my tank doesn't see over 77.7. I gotta come check your setup out! I think its modd time as airflow should solve your problem. Quote Link to comment Share on other sites More sharing options...
Bill B Posted January 13, 2010 Share Posted January 13, 2010 Good Lord Hydro...I have 2x250W over my 90G and my temp swings from 77.4-78.3 during the summer. In the winter my tank doesn't see over 77.7. I gotta come check your setup out! I think its modd time as airflow should solve your problem. Yes I am sure there are numerous setups that would tend to make tanks hotter or colder. When I first added three fans to my tanks in the summer (using two blowing over the lights and one sucking air out of the canopy) my 75 was borderline too cold some of the time until I varied the flow rate as well. At the time I was using 400 w MH and 220 w VHO. Bill Quote Link to comment Share on other sites More sharing options...
FarmerTy Posted January 13, 2010 Share Posted January 13, 2010 I'm glad you brought this topic up because I was thinking of going the same route with my 60-gallon. I should have all the hardware available to set up a second 250-watt metal halide but was worried about the heat due to my canopy that is not an open top. Currently I have one large fan pulling air out of the canopy but would like to setup another fan to pull air from the tank surface. Evaporation is not a concern for me as I have an auto-top off system in place. If it is needed, possibly even another fan in the sump. Am I going a little too light crazy? -Ty Quote Link to comment Share on other sites More sharing options...
[email protected] Posted January 13, 2010 Author Share Posted January 13, 2010 Good point about the evaporation rate. I'm adding an auto top off to the sump, but my sump is not that large. So if evaporation is too bad I might run the risk of draining the sump. I'm tempted to go back to my old setup of 2x175W MHs + 2x55w PCs. Thats what I was running on my old 72G and I never had any problems with heat or evaroration. I had a couple of small fans blowing on the bulbs by the way. Anyone want to trade 2 x 250W icecap ballast for 2 x175w ballasts (preferably electronic or a single dual ballast) Quote Link to comment Share on other sites More sharing options...
+Hydro Posted January 13, 2010 Share Posted January 13, 2010 I have (2) 250's over the 72 gallon (one on each side of the brace). This tank is plumbed into 2 other tanks and there is a chiller on the entire system so with both 250's its no problem keeping the temps around 78. I have however closed off the circulation between the tanks not utilizing the chiller for the 72. When I do this I'm only able to run one of my 250's...but like I said no fans are being used. Even without fans it would evaporate quite a bit. It really also depends on what the ambient room temp is that the tank is kept. If the lighting heats up the room... the higher the room temp the higher the tank temp will be if not using a chiller. Keep in mind on the last hour of lighting the room and the tank will be as warm as it will get. My office heats up to 78-80 degrees on the 11th hour so without a chiller the best I could expect is 80 degrees even if using fans. Quote Link to comment Share on other sites More sharing options...
+Hydro Posted January 13, 2010 Share Posted January 13, 2010 Instead of buying new lighting a 1/10th HP chiller would work great, they are about $300 for a cheap one. With a chiller you will be able to keep more stable temps year round and keep the lighting you want. I vote chiller and lighting!!! Quote Link to comment Share on other sites More sharing options...
[email protected] Posted January 13, 2010 Author Share Posted January 13, 2010 Hydro, Thanks for the offer on the chiller, but at this point my budget is pretty much gone that's why I would wither use my existing 250s or if I can work out a trade for 175s I'll do that. We keep the house pretty cool (around 75-76). Quote Link to comment Share on other sites More sharing options...
FarmerTy Posted January 13, 2010 Share Posted January 13, 2010 Eleyan, I think you're fine with the two 250-watt setup. Just add more fans and make sure you have a large enough reservoir for your auto-top off system so that your sump will never run dry. That hard part I have is fitting another metal halide in the canopy. Looks like 2 of the 4 VHOs have got to go to make room for the 2 metal halides and a reflector setup. I'll wire the new fans to blow across the surface of the water and link them to the metal halides. I'll let you know how my temps turn out, though right now it is not indicative of the summer conditions obviously. Quote Link to comment Share on other sites More sharing options...
Gonzobob Posted January 13, 2010 Share Posted January 13, 2010 My office heats up to 78-80 degrees on the 11th hour so without a chiller the best I could expect is 80 degrees even if using fans. Somewhat faulty logic in use here. The fans their cooling both by conductive cooling (moving heat from a warmer area to a cooler area as well as by promoting evaporative cooling which is quite capable of cooling a tank below room temperature. The limit of evaporative cooling is that it's efficiency decreases as humidity increases. Anyone feel free to add / correct if I’ve named anything incorrectly. Quote Link to comment Share on other sites More sharing options...
caferacermike Posted January 13, 2010 Share Posted January 13, 2010 I'm also going to chime in that I call bunk on the fact that you will have all kinds of problems with 2x 250w. Now I will admit that your 72g tank will indeed be 3g smaller than my 75g, however I have been running 2x250w MH w/ 2x96w PC for over 5 years now and have never had a concern. If anything I am considering adding another 250w set up for a total of 3x250w, or 750w MH. Quote Link to comment Share on other sites More sharing options...
[email protected] Posted January 13, 2010 Author Share Posted January 13, 2010 caferacermike, what kind of cooling do you have? fans blowing at the lights/sucking air from the sump ? Quote Link to comment Share on other sites More sharing options...
mFrame Posted January 13, 2010 Share Posted January 13, 2010 I'm also going to chime in that I call bunk on the fact that you will have all kinds of problems with 2x 250w. Now I will admit that your 72g tank will indeed be 3g smaller than my 75g, however I have been running 2x250w MH w/ 2x96w PC for over 5 years now and have never had a concern. If anything I am considering adding another 250w set up for a total of 3x250w, or 750w MH. Mike, you have an open-top canopy too, right? Just asking as I think it definitely has an effect. My 90g has a completely enclosed canopy with (2)250MH and T5 lighting. I have vaulted ceilings in the room and a total of 4 pc fans (2 pulling air into the canopy, 2 pushing out) and haven't had any temp issues. I also hae an ATO and currently use 1-2g per day, I expect more in the summer. Quote Link to comment Share on other sites More sharing options...
caferacermike Posted January 14, 2010 Share Posted January 14, 2010 Open top. Suspended fixture. No external fans. The fixture has 2 tiny little cpu fans drawing air through the fixture but it still gets hot, the fixture-not the tank. I keep it about 8" above the water. I'm really gearing up to gut it and add a 3rd 250w bulb. I built the fixture myself when I saw how much the Maristar was going to cost. Quote Link to comment Share on other sites More sharing options...
[email protected] Posted January 14, 2010 Author Share Posted January 14, 2010 The way I've done my other bowfronts lighting (both 175G and 72g) and the way I'll probably end up doing this one as well, is build a frame out of wood and pvc to hold the lights and fans. The Oceanic hoods for these tanks is only a flimsy plastic shell, so I can't attach anything to it, but the way I build the frame is that it fits completely under the hood. I leave the top and back of the hood open for air circulation. here are some photos of my 175 setup with 3x250W MHs + 2x55w PCs Quote Link to comment Share on other sites More sharing options...
+Hydro Posted January 14, 2010 Share Posted January 14, 2010 Gonzobob, I agree with you that evaporative cooling can cool a small body of water below room temperature but I don't think that the water surface of aquarium is enough heat exchange to bring the entire tank below room temperature, especially with the lighting on. If that was the case there would be any needs for chillers and all our tanks would be 72 degrees with just fans. I don't think it is possbile to bring the tank temp below room temp, I'm really curious has anyone out there been able to do that? Eleyan, I have a 175 bow and 72 gallon bow too, you have great taste . Neither of my tanks have a canopy and I haven't been able to find one for them either, I was forced to hang my reflectors from the ceiling. I used thin plastic coated cables to hang an aluminum bar about 20" over the tank, the wires run through the sheetrock and are secured to the rafters in the attic. I attached 3 reflectors and since they were exposed I used daystar reflectors from Hydrofarm...for now. I bought some hang on actinics from Sulight Supply that use magnets to attach to the reflectors. I'm going to change all that out in the next few weeks for a reflector that I designed (waiting on samples), I attached a pic. This is an aluminum 2' long version in anodized silver but for my tanks I will use a 6' long anodized black. I will be attaching a custom made anodized aluminum duct that will run behind the aquarium down to a fan that has a water-cooled heat exchanger attached. I'm going to be using a 2 port chiller that will cool both the tank and the water-cooled heat exchanger but will not be mixing the water. The fan will be connected to a thermostat that will speed it up and slow it down depending on the room temperature. This will add suplemental a/c to my office and cool the lights at the same time. I know it sounds like it's overkill but water-cooling is what we do, I'm an inventor/problem solver by trade and love tinkering with new ideas. Quote Link to comment Share on other sites More sharing options...
[email protected] Posted January 14, 2010 Author Share Posted January 14, 2010 Cool setup hydro. I like those reflectors. Unfortunately leaving the tank without a hood is not an option for me. I've had to fish out crayons and toys out of the tank before plus my arrangement with the wife is that no exposed equipment or wireing will be visible ( the tanks are in the living room) Quote Link to comment Share on other sites More sharing options...
+Hydro Posted January 14, 2010 Share Posted January 14, 2010 Thanks but honestly the canopy is better, the light bleeds out the side of the reflectors and is distracting, kind of takes some of the focus off the the tank. I hope my new reflectors won't be so bad since the bulb is farther up inside of it. If I had a canopy I would just hook ducting up to the backside of it and run down to my heat exchanger, it would be simpler for me. Quote Link to comment Share on other sites More sharing options...
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