Unfortunately with Terrors and most cichlids plants are usually not a good idea, as the plants will more than likely be uprooted at very least if not completely torn to shreds. As for the sand I personally use sand in my tanks and I've got 4 large CA/SA's and they like digging and sifting thru it. Many say it's easier to maintain than gravel, but in my experience it's just as hard to maintain as gravel. Though since the fish sift thru it they wind up kicking up alot of dirt and poop into the water column where it's more easily filtered so it stays cleaner longer. The hard part comes when you vacum(if you do) the substrate. Then it's a real pain trying to make sure you don't suck the sand up along with the dirt. Though in my opinion it's well worth the aggravation for the look and the fish and their natural instinct to root around in the substrate. As for the dithers it's gonna be nearly impossible to find something from the same area that won't grow too large for your set-up and the Green Terror to be in the 84 at the same time. The pink tail just won't work in your set-up because they naturally school and are very active and your tank won't have enough space for them to comfortably cruise especially once they get larger. You'd actually be better off sticking with Silver Dollars as common SD's and Spotted SD's get around 5 inches instead of the 10 inch Chalceus. Both are very active, but it's better to have a 5 inch very active fish than a 10 inch very active fish in your kind of tank. You can probably squeeze three in there if you really stayed on top of you water quality and made sure that most of the tank's swimming space is free of obstruction with the exception of one place for the Terror to be able to retreat to. Just keep the Terrors cave to one side and fill the background with some fake plants that can be suctioned to the back of the aquarium. This way the plants will take up virtually no room, yet still offer the SD's some place to be able to dive into if they get spooked. Also keeping the Terrors hide to one side and breaking line of sight with plants should help quell some of his aggression. As well as hopefully making him favor one side as his territory instead of him trying to rule the whole tank. It may or may not work, but it's definitely better than putting his hide dead center and then for sure he'll constantly be harassing the SD's for crossing his territory. One other thing the SD's might nip at each other when kept in a school numbering less than six, so it's upto you if you want to try the 3 SD school or not. They supposedly get along fine alone, but I've never kept them that way so I can't say for sure if that's true. I however have kept them in a school of three with no other problem than some nipping and not enough to hurt or damage each other. They just aren't as peaceful as when they're kept in larger schools. Well that's my two cents.I would also like to know:
Which plants, if any, would be suitable for having green terrors around?
Which substrate would be best?
Do they like playing with sand?
Thank you.
