Fluval Moss Ball 2"
Does lower phosphates - but raises General Hardness
I bought one of these to try.....I couldn't find anywhere online (or on the package) where it stated what the resin is. I used it in my 10 gallon freshwater aquarium for a short time. It did lower phosphates from 1 ppm to near 0 ppm - however, my GH raised to more than 8 degrees (General Hardness). I took it out, and put it in my 20 gallon. It lowered the phosphates from around 2 ppm down to less than 1 ppm - BUT raised my GH to more than 10 degrees! (I did leave it in the 20 gallon longer). I have many tetras which would get stressed with hardness levels that high. I took it out and did water changes in both aquariums (both now have GH readings where they should be. I also added more conditioner to detox the added metals). Other than a mild case of Ich with three new tetras - no real harm done (the three black neon tetras are already spot free - thanks to a long trusted product that is safe for all fish - and is available here at Drs. Foster and Smith). I use Reverse Osmosis water - and set the hardness to suit my fish. The only explanation was that the Fluval released Iron oxide into the water (I already confirmed that can happen with another Fluval product - company confirmed it).
This is the confirmation I got from Fluval about the Moss Ball:
>> "The resin in the Moss Ball is likely to be the same resin that is used in [the name of the other product]."
If your fish are not sensitive to ferrous/iron oxide, then you will be fine using this. I just know that it isn't good for tetras. Now that I use Reverse Osmosis water and can set the hardness (and pH), all of my fish are happy and healthy - and I am able to keep tetras.
March 26, 2012