Low pH/kH in Water, Low = Bad? Options

[Hamad]

I did a water test and my nitrate level is less than 10. There is no nitrite or ammonia, so the water is perfect and I do around 50% water changes every 2-3 days. There's also good filteration and high aeration and heater set at 30C.

But to my shock, the PH/KH are very low and they probably were for awhile because I did not test PH/KH for months as I don't buffer or try to make any changes to it. KH is less than 3d and the PH less than 6.4.

I did a test to the tap water and the results are very much the same. Does this low (but stable) level of PH/KH could have a side affect on the fish?

I notice that my fish usually show stress (very low energy) even though I feed a healthy mixed diet [different pellets, bloodworms, spinach, etc...] also as I mentioned earlier water is great and temperature at 30c which means fish should be more active than this. Could the PH/KH have something to do with this?

[Hamad]

I like the idea of coral chips/oyster shells, perhaps I should look for that. Thank you Gohks!

I read about adding baking soda in aged water and how it's not recommended, so what should I do in this case? I can't do a 100% water change and let these fish go through a cycle again, it will stress them.

Can I remove the fish, do 80% water change and then refill and add the baking soda and balance the KH at 4-5 as Sabine suggested? Would there still be a risk of adding the fish after this?

I guess this explains why the fish are sometimes not doing so well, everything else is done right and this is the only thing "off" that I discovered in my setup. Thank you so much Sabine, really appreciate your response, and thanks CyberET for your reassurance.

[CyberET]

I like the idea of coral chips/oyster shells, perhaps I should look for that. Thank you Gohks!

I read about adding baking soda in aged water and how it's not recommended, so what should I do in this case? I can't do a 100% water change and let these fish go through a cycle again, it will stress them.

Can I remove the fish, do 80% water change and then refill and add the baking soda and balance the KH at 4-5 as Sabine suggested? Would there still be a risk of adding the fish after this?

I guess this explains why the fish are sometimes not doing so well, everything else is done right and this is the only thing "off" that I discovered in my setup. Thank you so much Sabine, really appreciate your response, and thanks CyberET for your reassurance.

coral chips works too slowly to be effective, but u can give it a try.

pH up chemical works very fast, use with care.

what was it about adding baking soda in aged water u read about?

normally i do water changes with the fishes still inside, so that as i add water, the parameters changes slowly.. but becareful of injuring them if u r using a tube to siphon the water out.

after that, i'll add baking soda after water has been fully filled so that the impact of pH swing is not as great.

[awrieger]

coral chips works too slowly to be effective, but u can give it a try.

I agree. With Hamad changing 50% water every 3 days, he'll just be pouring pH6.4 water into the tank and it'll still be around the same by the time he does it again. So little will improve.

I'd recommend using a commercial KH Up product, which is usually Calcium Carbonate. Add it to the new water before adding to the tank if possible. If your w/c method is to use buckets or a container, then calculate how much is needed per bucket/container. If your method is a hose directly into the tank, Sabine's method is a good way.

Don't raise KH any faster than 1 degree per day initially. Your KH out of the tap is about the same as mine at 2.5. I raise it to 5 (so I'm only adding enough for a 2.5 increase), which stablises the pH at around 7.2 to 7.4 with heavy aeration.

All the best.