[Rupununi]

All,

I'm setting up a 125 S American cichlild/characin community tank. My source water is alkaline, coming in at 8.2 pH. I need a pH of 6.8ish for this tank given the species I intend to obtain.

I have purchased a Fluval FX5 and will use peat in the middle two media baskets as one step in reducing and stabilizing pH. Do you have other suggestions, beyond the "pH down" chemicals, for getting this pH where it needs to be and keeping it there?

Thanks!

Rupununi

 

[dotbomb]

You will probably need to buy RO water (reverse osmosis). My LFS sells it at $0.30 per gallon.

 

[fmueller]

The pH is unlikely to be your main problem. A high pH very often is an indicator for hard water, and a species requiring a pH below 7 will likely also need soft water. What dotbomb suggested will take care of both problems. Adding chemicals like pH down will not address the hardness issue, and increase total dissolved solids (TDS) - also not a good thing for fish that need soft, slightly acidic water.

If you have a 125G tank, buying water in bottles really isn't the way to go if you want to keep up with water changes. You either need to buy an RO unit, or look into African cichlids

 

[Rupununi]

The pH is unlikely to be your main problem. A high pH very often is an indicator for hard water, and a species requiring a pH below 7 will likely also need soft water. What dotbomb suggested will take care of both problems. Adding chemicals like pH down will not address the hardness issue, and increase total dissolved solids (TDS) - also not a good thing for fish that need soft, slightly acidic water.

If you have a 125G tank, buying water in bottles really isn't the way to go if you want to keep up with water changes. You either need to buy an RO unit, or look into African cichlids

Thanks guys for the input on RO water.

I actually do have a research-grade RO system at my university, which is where the tank will be housed. RO water doesn't necessarily have low pH if the source water that was treated had high pH, but the RO process does remove most if not all of its buffering capacity. So, of course the water is very soft given that virtually all of the TDS have been removed, but the pH is still around 8.

So, assuming I can adjust the pH down using peat or other natural materials (input here would be appreciated), my second concern is how folks keep pH stable in the mid 6's given the limited buffering capacity, e.g., those who keep discus or other Amazonian blackwater species?

Thanks again for the input, much appreciated.

Rupununi

 

[dielikemoviestars]

Are you planning on getting sensitive/wild fish? Because really, most tank-bred fish will be fine in a wide range of pH values. 8.2 is a littttttle high for that range, but still... Unless you're planning on angels/discus/other really sensitive fish, you probably won't need to worry that much.

 

[Rupununi]

Are you planning on getting sensitive/wild fish? Because really, most tank-bred fish will be fine in a wide range of pH values. 8.2 is a littttttle high for that range, but still... Unless you're planning on angels/discus/other really sensitive fish, you probably won't need to worry that much.

Well, a group of Geophagus is the plan, along with some complementary fishes from the Rupununi/Rio Branco portal region of Guyana. I'm still soliciting ideas from folks on the SA board about playmates for Geos, but would really like a pair or more of Biotodoma cupido, a school of tetras from that region, a pair of loricariids to be determined, and maybe a knifefish. I'll try to avoid super-sensitive species, but would like to get the pH down to at least neutral if possible.

Thanks for your input,

Rupununi