i picked up a 20 pound bag of crushed coral stuff in a 29 gallon long for cichlids. what type of cichlids would like this substrate and pH? i dont know what ph it is because i dont have a test kit yet i am going to order one of of ebay though.
The API Master Kit is good & is what most of us use for testing.
African rift lake cichlids like the hard water & high PH level but a 29gal tank isn't large enough for most of them. You would need to be very carefull about fish selection & you might find yourself restricted to a single species tank.
Those kits can test up to 800 times and you need to know how many tests are left if its used. If it new that's a good price and I would pick it up. Petsmart has it retailed about 35 bucks so depending on shipping costs you can decide where its worth it or going to the store and getting one. I don't know what the ph on crushed coal is but you should get the api master kit verse the test strips they are not as accurate.
A tank full of Fairy Cichlids (Neolamprologus Brichardi) would probably be my choice. Perhaps you might be able to have a Black & White Julie (Julidochromis Transcriptus) or Brown Julie (Julidochromis Dickfeldi) in there with them. A group of Two-Banded Cichlids (Telmatochromis Bifrenatus) woould be ok rather than the Fairy Cichlids. But that's if you could find them. There are several species of Shell Dweller that would work really well in a 30gal species tank.
You should wait until you know what the PH of the tank is going to be before you choose any fish. You don't want to decide on a fish only to find that your water is really soft & acidic & that the crushed coral only brings the PH up to 7.2 or something like that.
I already posted my suggestions in the other thread on this subject. I just want to say that I agree with harpua, mbuna really belong in at least a 55gal.
Not sure that N. Leleupi would be suited to a 30gal. Mine are about 7"now. Granted that is bigger than the usual 6" they get to. I don't think I'd want to try them in a 30 personally but it might work given that they move around a lot less & alot slower than mbuna.