Low PH & High Alkalinity: looking for suggestions to balance

TG17 · Tuesday at 1:26 PM

I recently purchased a 13.5 gallon reef tank that has been up and running for 18 months before me purchasing and moving it 5 weeks ago.

I keep all the rock, sand, and equipment, and about 50% of the water from before the move.

My PH is constantly low 7.2 - 7.5.
DHK has been rising and is now 12.

mostly soft corals, 3 fish (2 clowns and a tailspot blenny), a few crabs and a few snails.

Using Tropic Marin Pro Reef Salt (since the move). Been doing weekly water changes 3 gallons a week.

I've tried opening windows, adding a fan, turning way up my wavemaker so I feel like I have tried a lot to increase gas exchange, but have yet been able to get the PH to 7.8. I'm also concerned with the high DKH.

Mushrooms, Torch, Green Star Polyps, gorgonian look great, Zoa's seem shrunken/contracted, but they are open.

I'm looking for suggestions to help get the PH up and get the DKH down. I'd like to try and get the water chemistry right to the point that the Zoa's are happier, more open and growing.

Randy Holmes-Farley · Tuesday at 4:00 PM

I would not assume either measurement is accurate.
Try the alk kit on some of that new salt water.

How are you measuring pH?

smiley2024 · Tuesday at 4:04 PM

Are you using RO water for mixing salt?

Pls recheck with your LFS for these water parameters if u want to verify your test kits are not faulty

TG17 · Tuesday at 11:47 PM

smiley2024 said:
Are you using RO water for mixing salt?

Pls recheck with your LFS for these water parameters if u want to verify your test kits are not faulty

Thank you for the input yes using RO water and I’ve tested with the LFS. And they’ve confirmed what I’m testing. Using Hanna pH pen and Hanna alkalinity checker.

I have tested the RO water before and after salt pH is low 7677 is high 9 to 10

gbroadbridge · 2024-09-18T01:02:05-0400

TG17 said:
Thank you for the input yes using RO water and I’ve tested with the LFS. And they’ve confirmed what I’m testing. Using Hanna pH pen and Hanna alkalinity checker.

I have tested the RO water before and after salt pH is low 7677 is high 9 to 10

You cannot measure the pH of RO water. It has no buffering capability and can read anything at all.

How did you calibrate the pH pen?

My experience with the Hanna pens is that they are not very reliable unless you have bought the top of the line models.

TG17 · 2024-09-18T12:09:17-0400

Thank you for your reply. In regards to testing my RO water, I tested the PH after adding my Tropic Marin Salt mix, hopefully that makes sense.

For the PH Pen, I had the same concern, I use a PHEP+ pen, I have also been testing with another manual reagent kit and I seem to be getting the same results as the pen, so even if not perfect I think it is quite close. My thinking is if I consistently use the pen, it could be off a little bit, but using the consistent tech will allow me to have a pretty good sense of where it is.

Does that help?