Lewis wrote: <Try Ironite - available at garden centers, hardware stores, etc. A box <that costs less than $10 should treat normal aquarium volumes of water for <approximately a hundred years. If you use this stuff keep a close eye on the nitrite level. Ironites NPK is 1-0-0 (at least what I've seen is), so along with adding iron to your water column, you are also adding nitrogen. Bob Ashcraft