ph problem due to whole house CO2 problem.

[Geoff]

we apparantly have an extremely well sealed house. i have been fightin a ph problem since the tank was set up. the problem is the house itself. i did the 1/2 gallon aerated water jug test the last couple of day. the first day i aerated the jug next to the tank. when i tested the ph in the jug it was only .02 higher at first. within 15 minutes after the aeration stopped the ph matched the tanks. it was aerating over night. i next tried the jug outside on the deck. this morning i tested the water and the ph was .11 higher in the jug!

ok so now i know the problem, any ideas on how to fix a CO2 laden house. the way the house is laid out it is the house and not just a room.

Doug1- i may be able to blow air from the crawlspace below, but i have a feeling Newfiemom would not like the possiblilty of crawlspace critters visiting.

we have some plants, but it would need to be an insane jungle in the house to correct it that way. i will start trying to open the windows more at night, but due to the humidity of the area, it may cause our bill to go up because the A/C will be working harder during the day.

any ideas?

G~

[Mrs Smith]

I vote for the insane jungle idea. (And I'd also veto anything that would let crawspace critters in!)

Really, I have no idea. We have a very leaky house, so I'd never thought about the opposite. Good luck, though.

Danielle

[tdwyatt]

Originally posted by Geoff
the first day i aerated the jug next to the tank. when i tested the ph in the jug it was only .02 higher at first. within 15 minutes after the aeration stopped the ph matched the tanks. it was aerating over night. i next tried the jug outside on the deck. this morning i tested the water and the ph was .11 higher in the jug!

ok so now i know the problem, any ideas on how to fix a CO2 laden house. the way the house is laid out it is the house and not just a room.

Before you spend a lot of time and money pursuing this, get a Pinpoint pH meter and use it in your tank continuously for a while (if you already are, just forget I posted this ) There should be a daily swing in your pH as there is a CO2release and consumption pattern every day for your tank water that would not be matched by seawater held in a separate container. The presence of photosynthetic organisms in the water column will cause a daily swing from a low of around 7.95 in the mornings when the photoperiod starts to a daily high of around 8.2 to 8.6, depending on what organisms you have, your circulation, your alk/Ca supplementation regimen, and the number of specimens you have that employ photosynthesis (corals, macroalgae, microalgae and coralline algae). The larger the number of organisms and their related populations, the larger the swing each day. The sample container will not display this phenomenon, so we should expect their to be an overnight difference between the tank (which should be lower) and the sample jar (which should show little change once it reaches equilibrium with the atmosphere) This is not to say that the problem doesn't exist, but that this methodology might not be the way to accurately test your theory.

Total CO2 ( sigmaCO2 ) in seawater will very rapidly change to reflect the pCO2 in the atmosphere above the water column when it is rapidly agitated/circulated (See the Millero text, Dr. Millero states that this occurs so rapidly in surface waters that measurement of surface pCO2(atmosphere) can be one of the factors used to determine the buffering content of seawater (any two of the 4 following are necessary to determine the values in surface waters: pH, total alkalinity, sigma CO2(total), and the partial (atmospheric) pressure of CO2)) Bubbling or rapidly agitating the sample with inhouse air then comparing it with the tank and reeating this with outside air may more accurately reflect if this is an issue with your system.

If you know what your pH and your alkalinity are, you can determine the impact of the partial pressure of carbon dioxide is in each atmospheric air sample. The theory of the procedure to do this is in the Millero Text on pages 283 thru 291, and even includes methodology to account for the impact of decaying organic matter in the water column.

As far as actually supplying the aquarium with outside air, just run a length of clothes dryer vent and 4" PVC with a piece of screen over the intake end. Put a 4" muffin fan in the aquarium end over the sump to pull the air into the sump area. Should be all you'd need to do what you want.

HTH, this still could be the issue, but there would be a much larger difference in the pH that would show up after a brief (10 to 15 min) increase in agitation and aeration.

[Geoff]

Tom-thanks, i have been watching it on a monitor. i have a top off system that uses kalkwasser. i also have a refugium on a reverse light cycle.

i can believe the 10-15 min part of the CO2 equalizing readily in the water. i just read to do the test overnight, so i did.

a .11 difference is not significant to you? this would put my ph in the morning where i would like it just above 8. instead of 7.9 or below which it seems to be now. it could have happened within 10-15 mins. it also took me a minute to get the water over to the ph probe so it could have been a slightly larger difference.

"HTH, this still could be the issue, but there would be a much larger difference in the pH that would show up after a brief (10 to 15 min) increase in agitation and aeration."

with the jug in the same room it was only a .02 and i would agree. because of this i am sure that it is not a bio-load issue, which i was sure of anyway, but it is good to see proof. within 10-15 mins of turning off the agitator(had to to get it near the ph probe) the ph had matched the tank again.

if you can think of another test to try i am game. i have been thinking this has been a problem since our previous discussions on ph. on the rare occasions that i have been able to open the house the next day did show an increase in ph. those open house sessions were usually short before everyone goes to bed.

thanks again,

G~

[tdwyatt]

Originally posted by Geoff
a .11 difference is not significant to you?

Not in view of the circumstances of the test, yes, a difference of that magnitude would be significant, but uunder the testing methodology, I don't think that is applicable to your situation, although see below for the upshot.

more from Geoff...
this would put my ph in the morning where i would like it just on the rare occasions that i have been able to open the house the next day did show an increase in ph. those open house sessions were usually short before everyone goes to bed...

as always, the proof is in the pudding. If you open the house up and it corrects itself every time, then the CO2 is definitely an issue. It is not unusual for a heavly populated tank to have a pH in the 7.9 to 7.99 range, as the photosynthetic organisms stop using up CO2 at night and become net producers of CO2. If you have enough critters (this includes the corals as well as the macroalgae in the dark tank), it may be difficult for the reverse photoperiod sump to keep up with the CO2 production of the display, although this may be moot in view of the fact that airing out the house resolves the problem.

RickO is our resident HVAC man, and is more qualified to answer this aspect of the question, but I believe there are adjustments that HVAC units have to increase the percentage of outside air that is recirculated with the indoor air. This is DEFINITELY not an area of expertise for me, but hopefully he will see this post and respond. If not, the ductwork idea is clean, neat, and works.

HTH, btw, you two need to plan to come down in a few months, we will be doing another propagation program (if I can get Cath to make more of the minted Taboule again ) and I'll turn you onto some of the oceanography texts I have in the marine library.

[icebear]

if you decide you need insane jungle plants, gimme a holler

[SAT]

If you want to exchange more air without losing heat/cooling, there are exchange units you can get that hook into the HVAC. They work using a counter-current principle, similar to the gills in a fish. I understand they're SOP in Scandinavia.

[Newfiemom]

Wow!! Thanks for all the great ideas!

I do in fact veto any idea that involves allowing crawlspace critters into the house. Especially when they have 8 legs, but no legs isn't good either.

I am kind of liking the insane jungle idea, although it would have to be **really** insane (cathedral ceiling with a 26' apex, living room, dining room, kitchen and loft area all pretty much the same room) to make a difference I think...However if anyone has an really pretty African Violets feel free to send me cuttings I can root...

And as long as we don't already have plans on a particular weekend, we are always up for a road trip! Especially when there are aquarium goodies involved! Ryan is good for about 4 hours in the car before he gets tired of the car seat (it is 6 to visit the grandparents in GA), and the dog is optional.

In fact, since I have the floor, our best road trip goes something like this (Where's Spanky - he would love this): We were visiting a friend in Satellite Beach, which is about halfway down the coast of FL on the Atlantic side. We decided we wanted to take a day trip to Miami, because Geoff and I had never been and we thought the live rock prices would be pretty good (which they were). So after shopping for live rock we decided to go snorkeling on Key Largo, since we were already pretty much there. It was fun, but kinda dull (state park) so we took off down A1 (? - the main road in the Keys) and started looking for a better place to snorkel. I think we ended up on Big Key, anyway it wasn't great either (Spanky! Next time we need insider secrets!) but it was better than the first place and we were having a ball. What next? Dinner! Where? Well, we're almost to Key West, so let's just go there!

Dinner in Key West was yummy, but the service was stinky, and we left the restaurant about 11 PM. We all piled in the car, and Geoff drove us back to Satellite beach.

8 hours later, we were watching the sunrise from the car (well, I think I got a glimpse of it, anyway).



Poor Geoff...

Sorry that was so off topic, I had to share...

[CAT]

Maybe some kind of air exchanger would be good. Too much CO2 not good for humans either.

[Spanky]

ROTFLMAO

What a trip!

[geshields]

Geoff,

I had the same problem you do now. I corrected it by cutting a small hole in an exterior wall but stopped just short of the vinyl siding. 1/2" diameter. I then got an electrical box and cut the drywall to fit a standard single gang electrical box. I inserted 1/2" vinyl hose (black) into the electrical box and out the wall. I then used the expanding foam and sealed the electrical box and made the vinyl hose snug. I put a blank cover over the box with a cutout for the hose to fit through. I then ran this hose to the inlet of my protein skimmer. Constant fresh air being injected to my protein skimmer and that solved the problem. Until I put a CA reactor on the tank..but that's another story...

I was able to hide all the hose so no one sees it. And you can't see the hose from outside because it is under the vinyl siding.

Your house would stay sealed and your tank is kept happy.

Greg

[geshields]

BTW, we did look into air exchanger's but they were so expensive...I believe $1800 plus

Greg

[Doug1]

ouch on $1800 I think hose from underneath to the skimmer or sump area is a cheap fix and ya strainers will keep the willies out

[timing]

That is weird I am having a low Ph problem as well.
How does one go about the water test like you did?
Put a gallon jug fresh from the tap next to the tank and run a airline and pump on it or what?

[tdwyatt]

take a quart mason jar of your tank water, fill it hof ful with tank water, take it outside and fan the open jar for a few minutes to exchange the air on the surface of the water (do not fblow on it...), place the lid, agitate it well for 3 or 4 minures, then open it outside and let it air out for 30 minutes. Test the pH of the water with a known good test or meter (if it is a meter, use the borax test to check your probe and meter's accuracy).