pH crash, lesson learned

[bagpiper jim]

WOW, Until now I have enjoyed nice pH levels of 8.0 to 8.4 but things got fairly hot here today so the wife closed up the house and turned on the A/C. When I first got home things seemed fine but as the evening went on I noticed that one of my clowns was looking really stressed. I went straight to my aquarium closet and got my test kits and meters out and started testing the water. The only thing I could find was that the pH had dropped to 7.6. I immediately pointed my power heads towards the surface of the tank to get some movement across the top of the water and I opened the house and started the whole house fan to pull fresh air in. I turned off my light hood (only the 2 t5's were on) and within 10 minutes the pH was up to 7.75 and the clown was starting to look much better. It is amazing how quickly things can go south on you. It's also a good feeling to know that with a little quick action you can turn it all around and make things better. Amazing how fast the Co2 can build up when you close the house up for a day. This was a close call but I learned a lot from it.

Jim

[will16]

I had the exact same problem. It seems to only happen when I run the A/C. During the winter with heating its ok. What I did was run tubing from the air intake of my skimmer to a nearby window. Made a holder out of insulation and sandwhiched with the window. I also put a lock on the window so that it can not open any more than the crack for the tube/insulation. That way I leave it year round and not have to worry about it. Keeps my ph pretty steady.

[Constantin]

Dont think CO2 buildup is causing this...

[Lyfey]

My house is closed up and I use central air. I have no problems, I have never heard of this being an issue.

[IslandCrow]

Dont think CO2 buildup is causing this...

Actually, I think Jim's diagnosis is pretty good. The drop in PH was almost certainly caused by elevated CO2 levels, unless his alkalinity just happened to drop around that same time. Now, would it have killed anything. . .probably not. Could sub-optimal gas exchange at the water surface have been a contributing cause. . .very possibly. CO2 can build up very quickly in a house, though. During the summer when I generally keep the doors and windows closed almost all the time, if I open them up for even half an hour, I'll see a significant rise in my PH. I'm certain I'd see a similar change in my house's CO2 levels if I had a CO2 detector. For that matter, someone on this board was measuring the CO2 levels in his house, and it was almost scarry how high they were.

[Biologist]

While I understand why Bagpiper did more than one thing at a time (he's not doing a scientific experiment, he's just trying to get the pH down!), there's no way of knowing if just changing the powerheads to agitate the water surface would've been enough.

This is why the hobby has a lot of old wives' tales and myths. No one (myself CERTAINLY included) does things in a scientific way with controls, replicates, etc. I usually change about five things at a time, but I'm trying to stop doing that. :)

[IslandCrow]

I hear what you're saying, Biologist, and you're correct. I think the only conclusion we're drawing here is that a buildup of CO2 in the tank from the closed house caused a drop in PH. Given the circumstances and using the already proven concept that such a thing is possible, I'd say the theory in this particular case is at the very least sound.

Since he took more than one corrective action, it's impossible to say if all, some, one or none of them had an effect. But again, the overall conclusion is that reducing the CO2 levels in the tank caused a corresponding increase in PH. Since all of his actions could conceivable accomplish that, I'd say again we have a very sound theory that is more likely than not correct.

[Lyfey]

Why would'nt the powerheads be pointed towards the surface, to agitate the waters surface properly, in the first place?

[WaterKeeper]

The science experimenst go in the Advanced Topic or Chemistry forum. From what I see Jim you made the right moves.

When you have about 20-30 tanks in the house then you can selectively move powerheads and still have a control of their placement effect on pH. :D

[bagpiper jim]

All I can say is that I did everything I could do to increase the pH, short of adding buffer to the tank. The only difference from the previous day was that the house was closed up all day with the A/C running. All I could think of was Co2 had to be the cause. All of the other parameters looked fine. I have to say, even I was suprised at the increase in pH after making these changes.

Jim

[bagpiper jim]

Oops, how did that happen?

[WaterKeeper]

What Happen?

:D

[bagpiper jim]

<a href=showthread.php?s=&postid=15257249#post15257249 target=_blank>Originally posted</a> by bagpiper jim
Oops, how did that happen?

Admin must have fixed it but there was to copies of my last post.

[Sisterlimonpot]

<a href=showthread.php?s=&postid=15254404#post15254404 target=_blank>Originally posted</a> by will16
I had the exact same problem. It seems to only happen when I run the A/C. During the winter with heating its ok. What I did was run tubing from the air intake of my skimmer to a nearby window. Made a holder out of insulation and sandwhiched with the window. I also put a lock on the window so that it can not open any more than the crack for the tube/insulation. That way I leave it year round and not have to worry about it. Keeps my ph pretty steady. I always thought about doing that but the closest window is at least 20' away... I don't think that i'd get any air coming out of that tube after 20' of sucking

[mmedeiros2]

This link was my post that IslandCrow was talking about. I run a pump from outside instead of sucking the air in. If I don't run the pump to an airstone, the ph will not climb much at all during the day. IMO air has to be drawn, or pumped into the tank to minimize the prob. if your not dosing kalk. My results are prob. worst than most because I am dealing with a 10 gal. for now.
http://reefcentral.com/forums/showthread.php?s=&threadid=1530009

Lyfey - Mabey your house is larger, and less people and pets breathing in the house than most? Are any of the return air ducts leaking and sucking in fresh air? Not to mention you have a 125 gal. Just a thought. There is no doubt that high levels of co2 will drop your ph. I have watched it, proved it, and tested it. You would not beleive the difference with just my dog sleeping with me instead of sleeping alone. This is an issue with many. Try searching the posts and see what you come up with.

[dots]

I didn't catch where that Alkalinity and Ca test result was? Did I miss it?

[Toddrtrex]

This recently happened to a local reefer,
http://reefcentral.com/forums/showthread.php?s=&threadid=1658099
I have been to his place, it is a fairly new (( air tight )) place. Older places won't be as closed up and have less of an issue.

Lucky enough for me, mine isn't as bad when I have the A/C on, since I hate the heat. -- at least not as much of a drop as others have seen. My blue Haddoni does seem to prefer the window being open. When I test the pH it is still around 8, but it is normally around 8.3, been dripping more Kalk which seems to help. The anemone just doesn't open up a wide --- nothing else changes.

[Whys]

This is good to know. I've never seen this come up on here before and I never would have guessed CO2 levels could significantly affect pH within a few hours.

[bagpiper jim]

<a href=showthread.php?s=&postid=15265114#post15265114 target=_blank>Originally posted</a> by dots
I didn't catch where that Alkalinity and Ca test result was? Did I miss it?

Alk was 3.0 meq/L
and Ca was 395

Jim

[IslandCrow]

Yeah, Mike, that was exactly the thread I was thinking about. Thanks for linking it for everyone. I found it rather eye opening. I know my house is a newer one and sealed very well, which is normally a good thing, but even though it's just me (and the fish), it doesn't take long before my PH starts dropping if I haven't been keeping the doors or windows opened. I wanted to do the skimmer pulling in outside air trick, but it just wasn't very practical with where the tank was.

[mmedeiros2]

Hi Mike - IslandCrow, I think it was Michael from England that posted a pic of air tubing snaked up the wall into the attic. Nice job. The tubing went through a finish wall plate that was prob. mounted to a plaster ring for a nice finish look.
Also, a buttoned up house is not a healthy house. It might be cost efective, but there should be fresh air exchange. The last days of when I was wiring houses they were starting to build completly sealed homes. They would always have a system with small finish look fans that drew air in the basement and small finished fans in the ceilings on each floor would continue forcing the air through the house and into the attic. All nursing homes, hospitals, jails, and large buildings have to have air exchangers installed.
Here is a link to air exchangers for the home. This is the way to go for us and the fish ph issues. Having it done is another issue. Nice talking to ya.
http://www.airexchangers.info/air_exchanger_basics.html

http://www.otpco.com/ProductsServices/HeatRecoveryAirExchanger.asp

[Lyfey]

<a href=showthread.php?s=&postid=15264385#post15264385 target=_blank>Originally posted</a> by mmedeiros2
Lyfey - Mabey your house is larger, and less people and pets breathing in the house than most? Are any of the return air ducts leaking and sucking in fresh air? Not to mention you have a 125 gal. Just a thought. There is no doubt that high levels of co2 will drop your ph. I have watched it, proved it, and tested it. You would not beleive the difference with just my dog sleeping with me instead of sleeping alone. This is an issue with many. Try searching the posts and see what you come up with.

I actually gave it some thought. My apartment is only about 850 square feet. There is a window directly next to my tank which has been broken down into a 75 gallon with an oceanic model 2 sump. I had to move an hour away and I need to update my profile :) thanks for reminding me. I cracked the window about an inch and a half next to the tank. Its just my cat alone in the apartment when the lady and I are at work. I will test the differences now that I have some knowledge on the fact, and I have been doing some research on co2 levels since this topic has been started. Lets see if the crack does anything, last test of pH was on thursday I believe at 7pm was 8.1 with an Elos test kit. I will test again tonight at 7pm since opening the window yesterday. To make this expiriment directly not stable, I am in the process of converting over my bare bottom system to a 1-2inch sandbed. I believe this will effect the pH in its own. I have 1/2 - 1" in the tank now, I will add the rest of the ~10-15lbs of sand tonight. The sand is not live sand but will be when my culture from my 125 gallon (which is currently in its own 29 gal system) will be introduced.
Suscribed btw.

[Lyfey]

<a href=showthread.php?s=&postid=15264385#post15264385 target=_blank>Originally posted</a> by mmedeiros2
This link was my post that IslandCrow was talking about. I run a pump from outside instead of sucking the air in. If I don't run the pump to an airstone, the ph will not climb much at all during the day. IMO air has to be drawn, or pumped into the tank to minimize the prob. if your not dosing kalk. My results are prob. worst than most because I am dealing with a 10 gal. for now.
http://reefcentral.com/forums/showthread.php?s=&threadid=1530009

Lyfey - Mabey your house is larger, and less people and pets breathing in the house than most? Are any of the return air ducts leaking and sucking in fresh air? Not to mention you have a 125 gal. Just a thought. There is no doubt that high levels of co2 will drop your ph. I have watched it, proved it, and tested it. You would not beleive the difference with just my dog sleeping with me instead of sleeping alone. This is an issue with many. Try searching the posts and see what you come up with.

[mmedeiros2]

It is a lot easier to notice when using a digital ph monitor. Lets see how you make out though.
Now that the weather is warm, I have had my window open for over a week now 24 hrs./day. My ph hit an all time high after 5 days of the window being open. 82.5. With opening the window just in the day while at work, the ph would never go above 8.15. This shows that it took almost a week for the water to completely balance out, and this is only a 10 gal. tank. I would imagine that it would take somewhat longer for a larger tank. I will find out when my 75 goes up.