[sgarron]

I see this is a common problem, low ph that is. I've read all the threads and articles I could find but, I still have a ph of 7.8. It has actually been dropping to 7.65 at night. I recalibrated my reefkeeper and double checked it and it is correct.

My calcium is at 350, mag at 1300, dkh at 10. trates, trites, ammonia, all zero. I plan on straightening out my calcium issues this weekend.

I figured it was due to excess co2 in the house in the winter so I ran pvc pipe from the skimmer venturi, inside the wall, behind the crown moulding and out the side of the house. This was over a week ago and my ph is unchanged. I was able to bring it up temporarilly with baked baking soda but now that my dkh is 10, I can't do that any more. All my top off water runs through a kalk reactor.

Everything in the tank seems to be doing quite well, but I'm still concerned. I want to get to 8.2 or 8.3.

HELP!!! I'm stumped.

[pogodzib]

Assuming that your test kits are all accurate, my guess would still be that it is from excess CO2 if your not adding any chemicals besides kalk, although getting more fresh air into your skimmer should have helped. Have you read this article? Chemistry and the Aquarium IMO, it is the best article on the web dealing with pH in aquariums.

Take a bucket of water out of your aquarium and place it outside for a few hours with a powerhead or air pump circulation the water and rippling the surface. This will drive off most of the CO2 in the water. After you do that for a while, retest the pH of the bucket of water and see what you get. If the pH in the bucket is higher, you still have excess CO2 in your tank's water.

BTW - I have battled pH in the range of 7.65-7.8 in the past and the corals showed very little sign of stress. I know that it isn't anywhere near ideal, but, as you've already seen, your corals and fish can handle a low pH.

[sgarron]

I have read that article (several times). Can't really do the outdoor test right now, too cold. It's kind of funny, my ph was 7.85 this morning at 6:00. I didn't change anything, it just went up on it's own. I'm going to add a circulating fan above the sump to create more evaporation with will be topped off with my kalk reactor. Hopefully the additional kalk top off will raise the ph some more. My main concern was that I'm setting up a calcium reactor and they can lower ph as well. I think I'll leave it in the box until I can get my tank to stay above 8.1.

[pogodzib]

My guess would be that you'll notice your pH come up some when spring arrives and you start opening your windows up. As long as the water doesn't freeze, I don't know why the aeration test wouldn't work in the winter. Good call on waiting on hooking the calcium reactor up. You don't want to have to deal with adjusting it while dealing with pH issues before hand.

[bnhaus]

Tap water, fish waste, and a build-up of natural acids can make the pH levels fluctuate dangerously.

Experts say an 8.0 to 8.4 range is good. Some have even gone as far as 7.8 to 8.5 but that might alittle to extreme. Natural sea water is about 8.2 for reference.

What is your alkalinity levels at? Higher alkalinity can raise your PH also.

As posted by pogodzib, higher CO2 will lower PH. Check your levels.

Read this article, it may help.

Good Luck

Low pH: Causes and Cures by Randy Holmes-Farley - Reefkeeping.com

[sgarron]

It was my understanding that temperature effects ph readings. Even on the calibration solutions it states 7.0 at 77 degrees. I also read that the outdoor air test shouldn't be done in cold weather.

[sgarron]

Originally Posted by sgarron

My calcium is at 350, mag at 1300, dkh at 10. trates, trites, ammonia, all zero. I plan on straightening out my calcium issues this weekend.

RODI from day one. I have read that article several times, thanks .

[pogodzib]

Originally Posted by sgarron

It was my understanding that temperature effects ph readings. Even on the calibration solutions it states 7.0 at 77 degrees. I also read that the outdoor air test shouldn't be done in cold weather.

But you can take the water outside to aerate in and bring it back inside and heat it up. The CO2 inside the house shouldn't affect the pH significantly as long as once you bring the water back inside, you don't install the powerhead or air bulb that mixes the air with the water.

[sgarron]

Good point, didn't think of that.

[pogodzib]

Originally Posted by pogodzib

...or air bulb...

Incase you have an air PUMP instead of an air BULB, you wouldn't want to plug that in either.