View Full Version : How much crushed coral in filter?

11-25-2003, 06:48 AM
I'm setting up a 125 for African cichlids and want to try to maintain the proper PH by putting crushed coral in my Eheim 2128 canister filter. My question is how much do I need to put in there and which of the other two filter materials are most important to have in there along with the coral - the EHFImech or EHFIsubstrate sintered glass? And should I use the activated carbon pads?

My tap water PH is around 7.

11-25-2003, 08:59 AM
Well, you need a good amount, but there is no exact formula. Obviously, the more you put in the more buffering power. I wouldn't think anything less than a couple of cups would even be worth dealing with, and anything more would just take up space (it would, however, support bacterial colonization). I think the coral could take the place of the Ehfisubstrat would not be as effective in serving as a host site for bacteria, but you really need the coarse layer the Ehfimech provides to prevent the filter from becomng clogged too quickly (the Ehfimech is easy to rinse also).

Personally, I wouldn't do that though. There are to other options that would be less intrusive on the performance of your canister. My preference is to use a gravel or other substrate that buffers the water (but not crushed coral; too many sharp edges). Alternatively, you could add an air driven box filter filled with coral (and a little floss to prevent clogging). You could also decorate the tank with rocks that would buffer the water (like that white "Texas Holey" rock that so many African keepers use). Perhaps you could get an inexpensive hang on back filter (like an Aquaclear) and fill it with a bag of crushed coral. You'd also get some additional mechanical filtration that way (often a need in a tank filtered solely by a canister).