My nitrate reading is 40-80 before water change. nitrite 0, very soft water 60 ppm, kh is 40, ph is 6.4.

I add baking soda when it gets to 6.4. Then it goes to 6.8 or so. I cannot keep the ph up it goes to 6.2 at times.

I have some plants in the tank also and they are covered with brown alge and are somewhat ragged from the fish nibbling on them.

Could the ragged plants cause the nitrate read to be high.

With the low ph, I think my bio bugs are not doing too well. I really don't know what to do. I wish I could keep my tank ph stable...

Any suggestions?

Could a oyster shell in the tank raise the ph?

Please advise..

I dont think the plants would be making the nitrates higher, they are supposed to make them lower.. try to clean th plants a bit.. and dont clean the tank too often.

Hi Dixie

The low pH is of far more concern than the high nitrates; a total pH crash is quite possible if your water is so soft and acidic, and it will wipe out your fish if it happens.

You mentioned you added baking soda but the pH only rose as high as 6.8 and then dropped back down; the answer is simple, you didn't add enough soda. If you keep adding on the soda, a half teaspoonful at a time, the pH will eventually go all the way up to 8.2. However, I would aim for a pH of between 7.4 and 7.8 and a KH of over 80. This level of KH means there is enough soda - buffering capacity - to hold the pH steady where it is until the next water change.

You can also put oyster shell grit into the filter, which has exactly the same effect as baking soda and saves you having to add more soda at each water change. It will dissolve gradually over time as it becomes exhausted, so you just need to top it up with new grit every so often.

As for the nitrates, plants actually eat these so the more plants you have generally the lower your nitrate is. What kind of filter do you have? If it has sponges, you might find that rinsing these out in old tank water when you do your weekly water changes helps. Or you could try doing larger or more frequent changes.

Why do you want to change your ph? unless it is always changing by itself
if that is the case buy some chemi pure that will stabalize ph for about 6 months