Dear Jan:
If your total alkalinity is high but your pH is still a little on the low side, I would suggest discontinuing the buffer for the time being and instead adding one of the products designed to raise the pH of the aquarium rather than to buffer the water.
To adjust your pH to the proper range (8.1-8.4) initially, just obtain one of the commercially made products designed to adjust the pH upwards in saltwater aquariums and use it according to the instructions. Such a product should be available from any good LFS that handles marine fishes and invertebrates; they typically include sodium bicarbonate as their primary active ingredient and are often marketed under names such as "pH Up" or something similar. Just be patient when you are adjusting the pH and don’t add too much of the product too soon. Very often your pH won’t budge at all the first several times that you add the product according to directions. That’s perfectly normal, so don’t be discouraged if your pH stays at 7.9 even though you’ve added several doses of the product you obtained to raise the pH. Don’t don’t be tempted to add more of it or to add it more often than specified in the instructions. The product must first overcome the natural buffering ability of the saltwater in your aquarium before I can change the pH level significantly. It’s like performing a titration — typically, you add several doses and your pH doesn’t budge at all, but then the very next dose you add may change the pH dramatically. Since you never know when that critical point will be reached, remain patient and continue to carefully add more of the product as directed until the pH does start to change, and then adjust it to the desired level as gradually as possible.
In short, just be very patient and very gradually adjust the pH upwards, Jan. A pH reading of 7.9 is still within the daily fluctuations in pH most aquariums experience, and your seahorses should be fine at that pH while you take all the time that is necessary to safely nudge your pH upwards another point or two.
Once you’ve raised the pH to between 8.1-8.4, you can resume using your buffer again in conjunction with your regular partial water changes, and the pH should remain stable in the desired range. If not, let us know, and there are a couple of other things we can try to correct the situation.
Best of luck raising your pH and stabilizing your aquarium parameters right where you want them, Jan!
Respectfully,
Pete Giwojna
Ocean Rider, Inc. is an Organic Hawaiian-Based Seahorse Aqua-Farm & Aquarium that Follows Strict Good Farming Practices in Raising Seahorses and Other Aquatic Life.
