Rising ph in aquarium

[Tuydark]

Hi guys, I have kind of a problema here, my tap water has a I just recently discovered is acid (6.5) and once I put it in the tank over the time it only tends to become more acidic, how can I rise the ph to neutral? (since water changes wont help) i read somewhere online that I could put baking soda in the water ? will this not harm the fish ?? thx

 

[Colin_T]

Add some shells, limestone or dead coral rubble/ skeleton to the filter or tank and it will increase the pH.

Add a small amount and monitor the pH over a couple of weeks. If it hasn't increased, add a little bit more and monitor for couple more weeks. Continue adding small amounts until the pH gets to 7.0 or whatever you want it at.

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It also depends on the fish you keep. If you have tetras and angelfish, they will be fine at 6.5.
If you have livebearers or goldfish, they do better in water with a pH above 7.0.

 

[Byron]

Hi guys, I have kind of a problema here, my tap water has a I just recently discovered is acid (6.5) and once I put it in the tank over the time it only tends to become more acidic, how can I rise the ph to neutral? (since water changes wont help) i read somewhere online that I could put baking soda in the water ? will this not harm the fish ?? thx

Baking soda is not advisable, though one does often see it recommended. But there is more to this, and it is important to grasp all of the problem before considering action.

First, the pH is tied to the GH, KH and dissolved CO2 in the water. So the first thing is to ascertain the GH and KH of your tap water. The water authority may have this posted on their website, or you can call them. If you can test GH and KH, fine, but don't waste money on a test kit that you may only ujse the once. The GH and KH will not change much in an aquarium (we needn't get into the exceptions here).

Second thing is that as organics accumulate in any aquarium, they are broken down by various bacteria (not the nitrifying species here) and this produces CO2. There is also the respiration of fish, plants and some bacteria, all producing CO2. The CO2 creates carbonic acid which lowers the pH as it becomes more acidic. At this point, the GH and KH re-enter the picture; depending upon their levels, they may buffer the pH to prevent fluctuations. So again, we need to know these numbers to sort all this out.

This brings us to the fish. If you have soft to very soft water fish species, they will probably be fine in a lower pH. And a low GH too. With such fish, and assuming a low GH/KH and acidic pH, the fish will thrive. However, if you have fish requiring harder water and a higher (basic, above 7.0) pH, you will need to increase the GH/KH/pH. But the three are again connected, so it is the GH that is of prime importance; raising the GH naturally (with calcareous materials that slowly dissolve calcium and magnesium into the water) will also increase the KH and pH. Fish that need a higher pH almost always need a higher GH as well.

 

[seangee]

Hi guys, I have kind of a problema here, my tap water has a I just recently discovered is acid (6.5) and once I put it in the tank over the time it only tends to become more acidic, how can I rise the ph to neutral? (since water changes wont help) i read somewhere online that I could put baking soda in the water ? will this not harm the fish ?? thx

What fish do you have? My pH is close to 5 in one of my tanks and and I am quite happy about that, as are my fish.
When you say water changes don't make any difference what quantities are we talking about? Everything @Byron says is absolutely correct. I have 0KH in my source water but my pH is stable in all my tanks. The main reason for this is that I do a 75% water change in each tank every week. The old advice of 10-25% water changes really does not have much value. (APologies if you already know that )