View into one of the sumps showing a colander with Carib Sea Florida Crushed Coral.

My general policy is to favor good water quality and stable water parameters over achieving the exact water parameters that wild fish might find in a given biotope. For this Tanganyikan community tank I use NE Ohio tap water as the city of Kent supplies it. It has a pH of about 7.6 and a GH of about 8 and, as an aside, has been certified to be the 'Best Tasting Drinking Water'.

The water runs through a carbon block filter that is part of the continuous automatic water change (CAWC) system. This filter ensures that chlorine as well as any harmful heavy metals are removed, although I doubt that this is even necessary, since there is unlikely to be a significant amount of heavy metals in drinking water and chlorine would disproportionate faster than it could do any harm, due to the slow rate in which water is added. As a buffer, I am keeping 10 pounds of Carib Sea Florida Crushed Coral in the sumps. There are 5 pounds in a plastic household strainer in each of the sumps. These double up in purpose as biofiltermaterial. Only when performing major system maintenance and having the replace the entire sump contents I add the appropriate amount of Tetra Aqua Safe - a common dechlorinator and water conditioner - which I buy in pond quantities, due to the cheaper price. Actually, I picked up two containers that are sufficient to treat 35,000G of water for the princely sum of $20 at Ray 'Kingfish' Lucas' dry-goods auction in conjunction with the OCA Extravaganza 2006. I do not think I will ever have to buy water conditioner again in my life. Thanks Ray!

The only other additive I use is salt, and it is here that I deviate from my usual policy of stable water parameters. Salt is said to have various beneficial effects on aquarium fish, as for example this article by Marc Eliesen on Cichlid-Forum explains. I am using it with the thought in mind that a sudden increase in salt will increase slime coat production, and help the fish to get rid of eventual parasites. I do this about once per year in fall, and will add about 300g of salt to each of the two sump containers. Assuming a total system volume of about 300G, that's about 2g per gallon. If I added salt to the water continuously throughout the year, I believe the fish would get used to it and the effect of my fall salt regimen would be lost.