Need Help with High pH....8.5 - 8.7

[jschottenfeld]

Let me start by saying I've read over and over Randy Holmes Farley's article High pH: Causes and Cures, and after following what I he recommends I still continue to have high pH.

My 125g reef tank is about 10 years old and for many of the years ran smoothly with livestock living healthy and sps corals and zoas growing and thriving wonderfully.

Over the last 6 months I started to see an increased level of hair algae and pink cotton candy algae taking over my reef. Along with this I noticed that my Mexican turbo snail population was dying. I would check my reef chemistry and everything looked in normal ranges. New snails were purchased and they would last for a week or so and then die.

I had never thought to check my pH because for years and years it remained stable in the range of 3.2 - 3.4. After checking my pH (using my lab grade probe connected to my DA reefkeeper elite) it registered at 8.6. I was shocked. I researched and found the article that I mentioned above and started to treat with 3oz doses of white vinegar. It would temporarily lower the pH by .1 but by the next day it would be back up. I continually added about 3oz to 5oz per day, but the pH would keep climbing back up to the high levels.

Here are my current parameters:
pH ranges 8.5 - 8.7
Salinity 1.023
Calcium 385
Mg 1320
Alk 10.5
Nitrates and Phosphates undetectable
Temp 86 - 87.5

Only RODI water (0 TDS) is used for my weekly 15 gal water changes. I run a calcium reactor with effluent coming out at a slow steady stream at a pH of 6.6. I also use an Omega 180 protein skimmer that had recently stopped working (last couple of weeks) because of pump issues. I now have that back up and running. Since noticing the high pH I also started using an air pump in my sump. I also have a fuge with a ball of cheato tumbling under a light on a reverse period of my 3x250 mh lights over my display tank. BRS Mg supplement is dosed.

Because of this high pH I lost most of my large snails and just lost my beautiful maxima clam. I am at a loss of what to do to bring my pH back down to the normal range of 8.3 - 8.4.

Any help would be appreciated.

[karimwassef]

Do you have a skimmer? Try heavy aeration and it should equilibrate with the room CO2 level.

Also- I don't think 8.5 would be the reason your snails are dying? Check other reasons?

[jschottenfeld]

Yes, running an Omega 180 skimmer, and also added an electric air pump with air stone to my sump.

As an aside I couldn't figure out why my snails were dying.

[bertoni]

What is being dosed into the tank? Limewater might drive the pH up, but it's also possible that the problem is in the measurement equipment.

[jschottenfeld]

The only thing that I'm dosing is Mg.
I have not calibrated my probe in a while. Will check on that tomorrow.

[jschottenfeld]

I am running a calc reactor with a steady drip of 6.6 ph effluent

[karimwassef]

Get a separate check of pH

[bertoni]

I don't see any reasonable way for the pH to get that high if the skimmer is functioning properly. It should be providing a lot of aeration, assuming it's rated for something like the tank size.

[steallife904]

might try checking the calibration, I change out my ph probe every year to year and a half as well. they can go bad over time.

I noticed your salinity seems low and temp high. im thinking this is your issue. get salinity up to 1.025 or 1.026 and temp should be under 80, I believe up to 82 is usually ok but going up to 87 is hot! im thinking that might be the reason. This is just an opinion, would like an expert to chime in on that.

[tmz]

With a calcium reactor adding low pH effluent and what seems to be sufficient gas exchange via skimming and surface agitation I'd have to question the pH measurement as a first suspect.

[Anthony_MC67]

Hi. I am no expert but I would speak best on my research and personal experiences. Your PH maybe over the preferred level but it is by no means at a level that should be causing any trouble. I would start with bringing salinity up to 1.025 with a salt of good quality. My corals were sad until I started using Red Sea Pro. Now, considering that you have SPS I would look into slowly bringing your KH between 8 and 9 and your calcium up to 440.

Snail dying could be a concern but rather than paying more attention to that I would rather work on what is causing the algae bloom. If you are using other than LED lights then maybe your lights have lost their power having a change in spectrum that favors algae. Running lights for too long...For algae to thrive there has to be nutrients for it and you maybe having undetectable reading of phosphates because of them consuming it.

I hope that maybe one of those observations can help you.