If a higher pH is what you desire, and you have a problem with your aquarium’s pH, you may want to help buffer your water. pH buffers come in several different types but most are powders that can be added to your tropical fish tank and will help stabilize your aquarium pH. If you desire a higher pH in your aquarium water, you may also want to try to add a crushed coral substrate. This is a natural buffer and will prevent your pH from declining rapidly.
Update on how to lower Ph on a fish tank! - YouTube
I do have a RO system for drinking and I can confirm that it does in fact drop the PH level significantly. From 7.6 to 6.4. I inherited a 20G community tank, that I’m still trying to find out what kind of fish are in it. A Few Guppies, neon’s, nothing too exotic. That being said, I found myself guilty of over feeding after a while and one of the larger fellows began to swim tail down. From what I gather, it may be a bladder infection and I’ve had no luck trying to feed it a pea. The PH level was above 7.6, so I assumed the ammonia was too and did a40% water flush and thinned out the feeding. Finally did proper nitrate test and found it to be 0 after the flush, but the PH is still high between 7.4 – 7.6. Just finished reading this article and happened to have some peat moss that I added into the filter, so I will see what happens in few days. Curious about the gravel, which is store bought. Wondering if you could shed some light on this. Also I wonder about the plants, which are again store bought, but likely some degree of plastic. Might just take them out and see where things go if the peat moss is not able to lower it. Given that the RO drops the ph down around 6.4, yet the tank is at 7.6 there is obviously something raising the level.
Fish & Tank Care : PH Testing for Fish Tanks - YouTube
If you observe these symptoms in your aquarium and testing reveals pH levels to be high, you must slowly bring the ecosystem back into balance over the course of a few weeks. A rapid change in pH is even more harmful to fish than elevated pH levels, and may result in organ failure and consequential death. Many products are available over the counter for raising or lowering pH: always follow the label's instructions to the letter, and don't adjust your tank by more than 0.3 units of pH per day. A slow changes gives your tank's inhabitants time to adjust.
High PH Levels For A New Tank With No Fish | My Aquarium Club