Well water. R/O is still 7.6.

[Kharris453]

Hi! So I've been trying to lower my ph in my tank from a staggering 8.4. I was wondering if i should use distilled water because I've been doing water changes with my R/O and some "api PH DOWN". It doesn't seem to be working that well I've done about 4 water changes with that method. Perhaps my test kit is flawed, or more likely I used it wrong? I use the api master test kit. I was thinking about getting pest moss in the filter. All my other levels are fine, just the ph that needs work.

 

[fluttermoth]

It's best not to try and change pH; it's not very important for most fish, it's hardness that's more important to get right.

What sort of fish do you have? What's the hardness of your tap water? Are you mixing the RO water with tap water or a remineralising mix?

Sorry for all the questions, but the more information we have, the better we can help

 

[Byron]

Agree. The pH is linked to the hardness, both GH (general or total hardness) and KH (carbonate hardness or Alkalinity). The latter especially works to "buffer" the pH to prevent fluctuations. So attempts to lower (or raise) the pH will not work if the GH and KH are sufficient to work against this. The result, fluctuating pH levels, is far worse on fish than a pH that is somewhat out of their preferred range, generally speaking.

We need to know the GH and KH and pH of the source water, mixed water and aquarium water. You should test the well water on its own. Then test the mixed water (your mix of well water and RO water) after being mixed but before it goes in the aquarium. Third, test the aquarium water for all three. These numbers will tell us what is occurring.

The pH in the aquarium may lower, or not, depending upon the above results, due to the normal organic processes. It might also rise if there are calcareous substances dissolving mineral (rock, some substrate gravels). But without knowing the initial levels for GH, KH and pH, this is impossible to predict.

 

[Kharris453]

Thanks for the quick response! I've just ordered a gh/kh test kit from Amazon should be here in 2 days. I will test the water as soon as I get it and post the results. Thanks again!

 

[fluttermoth]

Do, please, let us know what kinds of fish you have; they might be ones that like or need a high pH and hard water!

 

[Byron]

Yes, I missed that. Species of fish you have/intend. And it probably didn't need saying, but I also neglected to suggest you not use any pH adjusting chemical, these are hard on fish and as you've seen don't have much effect. Once we have the numbers and know the fish we will be able to work this out.