The Maroon Lagoon V2.0

[Gig 'em @ NDstructible]

It very well could be taking in stale air, the pump is suspended in the top corner of my back yard patio. Not much of a breeze in there. I'm sure I could move the pump further out, but I'm afraid of a heaving rain storm getting it wet and frying it.

I'm curious what it would look like if I hooked up a zero air generator used for high precision air monitoring analyzers and ran it's air into the tank over night. The zero air generator has scrubbers and a thermal oxidizer that would remove most air contaminants. That could demonstrate if the air that's being drawn is stale.

You've got some fairly low levels of CO2 in your house Dan. I see levels over 1,000 ppm every night with the windows closed and my wife and I inside. I know I'm full of hot air, but sheesh! Do you have house plants or keep any windows open?

[FarmerTy]

I think you're the anomaly Gig'em. My house hovered around 600-800 ppm if I remember correctly. I'm sure it's a function of how airtight the house is as well as square footage... plus if your HVAC cycles in fresh air or not.

[victoly]

Just a thought, i don't know what your skimmer setup looks like, BUT, where you have your probes and where your fresh air is coming in could have an impact on your pH and carbonate dissolution. I suspect you're just monitoring pH in your sump and then your effluent. I would posit that a setup that looks like this: skimmer->CaRx->pH probe could have a verrrry different pH response than CaRx->skimmer->pH probe.

I guess before I speculate too much, what does your sump setup look like? I looked back through the build but the sump picture was pretty fetal in terms of your tank development.

[FarmerTy]

Man, you're the only guy I know Victoly that can get away with using the descriptor "fetal" in a post and it still read correctly. [emoji23]

[victoly]

It very well could be taking in stale air, the pump is suspended in the top corner of my back yard patio. Not much of a breeze in there. I'm sure I could move the pump further out, but I'm afraid of a heaving rain storm getting it wet and frying it.

I'm curious what it would look like if I hooked up a zero air generator used for high precision air monitoring analyzers and ran it's air into the tank over night. The zero air generator has scrubbers and a thermal oxidizer that would remove most air contaminants. That could demonstrate if the air that's being drawn is stale.

You've got some fairly low levels of CO2 in your house Dan. I see levels over 1,000 ppm every night with the windows closed and my wife and I inside. I know I'm full of hot air, but sheesh! Do you have house plants or keep any windows open?

Atmospheric gasses mix almost instantly. I'd wager that your CO₂ woes aren't a function of intake placement at all. It's probably bias in measurement of CO₂, measurement of pH (probe location, solidness of calibration, etc) or some other application issue (how or where the measurements are being taken or the fresh air is mixed into the water).

[victoly]

I have a paper on natural pH swings, that I'm trying to find a way to upload....

Anywho, my first thought was, how much pH swing do we see in nature? How much is acceptable in tank? Are we trying to over control?

What I came to was that we are actually GREAT testbeds for the effects of high CO₂ on natural coral reefs! Global CO2 just hit 400 ppm, but our in-house CO₂ levels are sometimes 2x that!

The paper I read shows swings of 0.2 per day. Maybe that's a good set point to shoot for.

[Gig 'em @ NDstructible]

Here's a pretty terrible photo of my sump. To explain from left to right:

Left: Skimmer with effluent from the biopellet reactor.

Center: Return pump, feeder pumps for the biopellet reactor, CaRX, and carbon/GFO, and the effluent line for the CaRX.

Right: fuge with rubble and chaeto and the probe rack with temp and pH probes.

The right side of the sump is elevated higher than the left side, so it is almost always flowing down away from the probes and the CaRX effluent has to pump up to the DT before it can return to the probes.

Here's an updated shot of the DT. Spent a couple hours rearranging and gluing corals down. So far I'm liking the look of the frag bridge. Just ignore the ugly white plate with my newest anemone on it.

[victoly]

I bet your pH reading is heavily influenced by the chaeto being so close to the probe. What would be really interesting is to see if your DT pH and your sump pH is appreciably different. I think that because of all potential modifications you make to sump water (aeration via skimmer, chaeto, aeration via outdoor air, CaRx effluent) that there are probably micro-zones where your pH is equilibrating to the tank at large.

Where is the influent to the tank and how does water fill the right chamber?

[Gig 'em @ NDstructible]

Oh I'm sure some you're right that areas of the tank have zones where the pH is different. I didn't want to put the probes next to the skimmer and I didn't want them by the return pumps either. If I could have them up in the display tank, that would be ideal, but I wouldn't want to look at them all the time. Maybe I'll try putting them in the overflows to monitor the DT water that is about to enter the sump. That may be the most accurate representation.

So if the pH probe is being biased at night with the chaeto (which I have suspected for some time, but don't know to what extent... ), then my concern that the pH at night is getting too low is valid.

The return lines from the sump are on the inside corners of the overflow. You can see them pictured in my DT update photo above. I have them pointing down towards the center water column where the PHs will distribute the water most efficiently throughout the tank.

[Dan H]

My house will hit 1000 when I have people over or sometimes when we just don't go outside all weekend. Also, since the tank has an exhaust fan, it's pushing out air from the house which will pull in air through cracks and seams elsewhere. So I'm sure that's helping keep the CO2 down some.

[FarmerTy]

I wouldn't put the probes in the overflows. If there was ever a situation where the return pump stops, your pH reading would only be indicative of the pH in your overflows and would not represent the sump or display tank. That could cause some potential issues.

If it were my tank, I would be less concerned with the amount of variance seen in the day and more focused on increasing the overall range. Hopefully the outdoor air aeration will help increase your overall range.

[Gig 'em @ NDstructible]

Just curious Ty, what issues are you referring to if the return pump stops? If it would go out for some reason that wasn't a power failure, I still wouldn't get a representative reading of the true conditions of the tank with the probes in the sump. They only thing I can think of is if the pump stops working, the temperature drops in the tank, and the heaters would come on and only shut off when the temperature setting of the heaters was reached, but still raising the temperature of the sump above the desired range.

I did move the probes closer to the overflow pipe in the sump so the probes would read more DT water and have less impact from the chaeto. We'll see what that looks like over the coming days.

[victoly]

Oh I'm sure some you're right that areas of the tank have zones where the pH is different. I didn't want to put the probes next to the skimmer and I didn't want them by the return pumps either. If I could have them up in the display tank, that would be ideal, but I wouldn't want to look at them all the time. Maybe I'll try putting them in the overflows to monitor the DT water that is about to enter the sump. That may be the most accurate representation.

So if the pH probe is being biased at night with the chaeto (which I have suspected for some time, but don't know to what extent... ), then my concern that the pH at night is getting too low is valid.

The return lines from the sump are on the inside corners of the overflow. You can see them pictured in my DT update photo above. I have them pointing down towards the center water column where the PHs will distribute the water most efficiently throughout the tank.

I should have said where is the influent to the sump.

Youll see a more exaggerated pH swing near the chaeto. During the day while its photosynthesizing, it's pulling out CO₂ to make sugar, and during night it is producing CO₂ through respiration. If that scenario is accurate, then you'd have a lower pH than you might have in your DT.

As far as keeping the probe in your overflows and having that be representative, i guess it depends on how much spill you have. The more turbulence, the more atmospheric mixing. I'm advocating dropping that sunufagun directly into the fat middle of the DT for a few days and seeing what happens.

[Gig 'em @ NDstructible]

Wouldn't be bad. I should have done that this morning before I left for my trip since there's no one to care if there are some probes in the tank this week. The influent to the sump are one into the left section of the sump with the skimmer and the other into the right section of the sump with the chaeto.

Here is a picture of my CO2 levels in the middle of my house this morning as proof of my issue.

#smallhouseproblems

Edited May 18, 2016 by Gig 'em

[Reburn]

You could always. #breatheless.

Or try to get some house plants

[Gig 'em @ NDstructible]

I told you, I'm full of hot air, there's no stopping it. [emoji12]

Yeah, definitely going to try some house plants out. I just don't have enough natural sunlight in my windows and my wife loves to neglect plants while I'm out of town. I feel like they would just die. I guess I could have a grow lamp that turns on at night to help reduce CO2 levels at night.

[FarmerTy]

Victoly, that CO2 meter look familiar?

For the probes in the overflow, I was just thinking if you had any probe dependent programming, that the overflow would not be truly indicative of your tank conditions if the return flow ever ceased, but you are right, it would be a similar issue in the sump, though at least it would be a large volume of water and may give a reading closer to actual conditions then the finite amount in the overflow.

[Gig 'em @ NDstructible]

Yeah I see what you're saying Ty. I don't have many rules set up outside of turning off/on fans and heaters and the heaters have their own "fail safe" setting if they get left on. My CaRX may also shut off if pH gets too low, but I doubt that will happen with my settings. I'm not as much of a wizard with my programming as you are Ty!

[FarmerTy]

Yeah I see what you're saying Ty. I don't have many rules set up outside of turning off/on fans and heaters and the heaters have their own "fail safe" setting if they get left on. My CaRX may also shut off if pH gets too low, but I doubt that will happen with my settings. I'm not as much of a wizard with my programming as you are Ty!

I think monkeys could program better than I can so don't give me too much credit. Most is borrowed code anyways.

Want me to move your probes to the DT while you're gone?

[victoly]

Victoly, that CO2 meter look familiar?

For the probes in the overflow, I was just thinking if you had any probe dependent programming, that the overflow would not be truly indicative of your tank conditions if the return flow ever ceased, but you are right, it would be a similar issue in the sump, though at least it would be a large volume of water and may give a reading closer to actual conditions then the finite amount in the overflow.

Hah, yup. Glad its being used to fuel the advancement of this reef forum.

I told you, I'm full of hot air, there's no stopping it. [emoji12]

Yeah, definitely going to try some house plants out. I just don't have enough natural sunlight in my windows and my wife loves to neglect plants while I'm out of town. I feel like they would just die. I guess I could have a grow lamp that turns on at night to help reduce CO2 levels at night.

Honestly you're probably better off either just using outdoor air for your simmer intake OR using soda lime to remove CO2 to the skimmer intake.

[Reburn]

Victoly, that CO2 meter look familiar?

For the probes in the overflow, I was just thinking if you had any probe dependent programming, that the overflow would not be truly indicative of your tank conditions if the return flow ever ceased, but you are right, it would be a similar issue in the sump, though at least it would be a large volume of water and may give a reading closer to actual conditions then the finite amount in the overflow.

Hah, yup. Glad its being used to fuel the advancement of this reef forum.

I told you, I'm full of hot air, there's no stopping it. [emoji12]

Yeah, definitely going to try some house plants out. I just don't have enough natural sunlight in my windows and my wife loves to neglect plants while I'm out of town. I feel like they would just die. I guess I could have a grow lamp that turns on at night to help reduce CO2 levels at night.

Honestly you're probably better off either just using outdoor air for your simmer intake OR using soda lime to remove CO2 to the skimmer intake.

DUDE? WTF? I wanna see a jungle of pothos ivy since it can't be killed and his c02 at 950. Don't spoil my dreams.

But seriously, everyone says skimmer line drawing outside air will work I have done it and your like, nah bro, some idiot says get some house plants and your like that's is a marvelous idea......and for the record indoor plants with grow lights usually gets the cops called on you.

[Gig 'em @ NDstructible]

If the constant glowing blue lights come from half my windows hasn't gotten the cops called on me yet, I don't know if anything will!

Ty, if you want to climb through the rats nest of wires and put the probes up top, you're more than welcome to in the name of science and our own curiosity on the forums. Just make sure you properly secure that ATO line, I don't want to be getting wet floor alerts while I'm hiking in the alps.

[FarmerTy]

Hmmm.... maybe I'll wait. The last time I touched your tank, you had unsecured lines laying around and I knocked a line out. Not sure I want to be moving cables if you haven't decluttered yet and while you're out of town. It'll ruin my Saturday night party I'm throwing at your place if everyone comes over to wet floors and the smell of dead corals and fish.

[Gig 'em @ NDstructible]

Well, at least you could make a slip and slide in my house for your party! Break out my windows while you're at it please.

[FarmerTy]

Well, at least you could make a slip and slide in my house for your party! Break out my windows while you're at it please.

First time ever anybody had been thanked for busting out windows.