Trying to decide on stocking list for 90 gallon; currently decided on 4-5 geophagus redhead and 20 lemon tetras. Does anyone think I'd be alright with one threadfin Acara as well in that setup? Will it get on alright with the geos?
Wow, the dedicated Biotope aquarium odyssey continues!
So, did you decide on the Rio Tapajos as your river? if so? Great!
And yes, a single Threadfin Acara would stock really well with your Geophagus sp. Tapajos group. They are a cool looking cichlid you don't see very often. He (or she), will almost certainly be the centerpiece/dominant fish for the aquarium! 8)
I would go with a slightly smaller group of Lemon Tetras - 14 to 16 should be plenty. Remember, the priority in success will really depend on how well you can keep the more sensitive cichlids stocked in that tank. A Threadfin Acara will not be - quite - as sensitive to poor water quality as your Red Head Tapajos Geos will be.... but unfortunately, they come close.
- Go with a 1M-4F harem of Red Headed Tapajos. As I said earlier, the males of this Eartheater species are known to be pretty hard on the females stocked with them. Your gonna need at least four females to spread out the aggression and keep any of the females from getting harassed and stressed by the male too much.
- Test your tap water! Hopefully you come from an area that has zero Nitrates in the tap water? Plus, check the PH and GH. If you have alkaline water, that is at a reasonable (NOT Liquid Rock, Hard Water) level - you should be able to use the water supplied 'as is', (dechloramined) right out of the tap for your tank.
So yes, you're gonna need to be diligent in maintaining high water quality. And, keeping the fish stocking bio-load for your aquarium down to low levels, will definitely help you to do that. :wink: