Help with pinpointing pH problem.

[FloridaFishMan]

Hi,
I have been trying to get my pH to stabalize but it always seems to drop. After a water change or after the addition of a Ph buffer it will go back to ~8.2 but of the next few days it will drop down to ~7.8 and I can't figure out why. All my NH4, NO3 readings are 0ppm. I have good water circulatoin with one return from my refugium and a 160gph ph. The tank is 30gal. The sand I have was tested using vinegar and it fizzed. I feed once a day and all the food is consumed. Can anyone shed some light onto my problem and some possible fixes?

thanks,
Chris

[Poolrad]

Do you test at the same time & same spot each time? Lots of PH fluctuations in location & time. How is your gas exchange?

[FloridaFishMan]

I test at relativly the same time and place. I have also tested at different times and it seems to change little through the day (a small rise by the end of the day). I would like to think my gas exchange is good enough (I may be wrong). The overflow box picks up air as it drains down and I have a protein skimmer that should help as well.

[Poolrad]

Do you have a closed top tank? How about surface agitation?

[FloridaFishMan]

Also I have an eggcrate cover on my main.

[FloridaFishMan]

I run a fan during the day to cool the tank. The fan blows directly on the surface of the water at an angle. Also the return creats some surface agitation when the fan is off.

[mystikdragon7]

Do you have anything else in your tank pushing more water? 160gph seems to be a little on the low side. How high does your PH get at the end of the lighting cycle? Ph will always drop a little after the lights go out. Having a fan, skimmer, and good water agitaion at the top should bring in enough oxygen. Try taking a cup of water outside and swirl it around and then test for PH. If it goes up then the chances are you are not getting enough oxygen into your tank. Try opening a window next to or near your tank to get some outside fresh air.

[FloridaFishMan]

I also have a return pump from my refug that is pushing between 350 and 400gph my estimation. I have run that test. I took a water sample and ran in with an aerator for an hour and there was no change is pH. That was a few days ago when the pH was ~8.1. I am going to try and rig my refug so the lights are on when the maine tanks lights are not. I have been letting those lights stay on a little longer but they keep me awake so they are off when the top lights are off. But regardless there are people who don't have refugs and there pH stays more constant. Do you have any other suggestions?

[FloridaFishMan]

Would it possibly help if I pointed the ph at the top of the tank?

[menace]

how is your alk? having a higher alk will help prevent ph drops.

[FloridaFishMan]

I don't have a test for alk but I do add the buffer increaser which should also increase alk.

[Billybeau1]

You should test for alk. Very important. Go to the Reef Chemistry Forum and click on the reef chemistry articles by Randy Holmes-Farley. He has an article in there about PH problems and cures. Should answer most of your questions. Good luck

[originalozzyo]

Also avoid using buffers that are supposed to help raise your ph, they also raise your alk without you even noticing it unless you are testing that as well. I learned the hard way when i lost a large frogspawn and a lobophyllia in a week

[menace]

you should really test your alk. without knowing what demand the tank has on alk you would not know how much to supplement.

[FloridaFishMan]

Just testes alk and it is well in the good range so it isn't the alk. Any other suggestion?

[uh60chief]

Are you using red sea test kits?

[rtc_reefer]

What is the "good range"? Which test kit did you use?

[FloridaFishMan]

Well I just read the thread about reef chemistry and I now believe them to be in the not so good high range. It registered as high as it would read so I think it is over. I used a drip test kit.

How can I go about raising my pH without using the pH buffer? I am in the process of reading the links from the chemistry page but in the meantime I was wondering what you all use? Also should I do a water change since I believe my alk is high?

[rtc_reefer]

1) get a good ALK test kit from Salifert.
2) Save some money and use Randy's two part Ca / ALK / Mg
3) I have had no problems since I stopped using commercial mixes.

Hope that this helps.

[smoknreefrs]

water changes always seemed to help me out when i had chemistry problems

[FloridaFishMan]

Update: I just did the aeration test outdoors and the pH increased dramatically! I did the same indoor test when the pH was relativly high and there was no change. Is there someway I can rig my aerator to run outside to pump in fresh air? Also I live in Florida and keeping a window open isn't possible since it is 94 during the day. I am running the aerator in the same water right now indoors to see if the pH decreases (which I am certain it will).

[reefez]

Some people run air to the skimmer hooked to a outdoor pump.

[FloridaFishMan]

I just did a 4gal water change but before I aerated the water outdoors. I have connected a temp line to my skimmer that is getting air from outside my window. I think this will help, at least I hope so. Thanks for all the help!
Chris

[rtc_reefer]

I'd like to know the results of the outside air test you are doing simply for personal knowledge ... if you wouldn't mind.

Thanks!

[FloridaFishMan]

The indoor test gave me a pH of 7.8. The outdoor test gave me a strong result of 8.4 or even maybe a little larger. A large difference. The pH indicator went from a pale brown to a deep purple! After I aerated the same outdoor air that gave me the 8.4 reading indoors, I got another reading of 7.8. So hope fully in a few days the pH will increase steadily (along with O2).