Another low-tech - zero water change - discus tank idea.
i have been keeping/breeding fish in ecosystem setups for years without filtration or water changes. the disadvantage is very low bioload. since i've only ever had tanks in the 20ish area before, 55g being the largest i've ever owned, this meant fish in the 1-2" ranges. i've always considered 3" a "monster fish." i'm now setting up 240g tank with a 100-150g sump, so 350-400g total volume, and decided it was time to try my hand at discus. i'd like to get any thoughts or opinions on my setup as it's in the construction phase before it's up and operational.
ok, so the tank will be the 350+ gallons previously mentioned 8'x2'. the filtration will be the entire setup, with deep sand beds both in the display tank and sump. aerobic bacteria will inhabit the first 2" of the sand bed, as well as any other surfaces in the tank, and anaerobic bacteria will inhabit the 2" and below area of the sand bed. i plan to mix peat into the sand bed to provide a carbon source at the initial setup, but i don't plan on "recharging" it at a later date. instead i'm hoping that the fall of detritus will be enough of a carbon source at a later date.
as far as the substrate, i plan on using a mix of play sand from home depot and natural clay kitty litter. this will be my first experience with kitty litter as a substrate so i have some concerns, but it would be way too expensive to use fluorite in the quantities i need.
in the display tank i was planing on a 1/2-1" bottom layer covered with sand, and in the sump tank i was planing of a 50/50 mix amounting to a 5"ish layer. one of my concerns is the clay chips rising enough in the substrate to cause an issue with scaleless sand dwelling species.
my next concern comes from the lighting. i was planing on using a few LED screw in bulbs. i was thinking something like 6x 1000 lumen(13w) 6500k, but i can switch that over to 5000k and add or subtract as many as are needed. being screw-ins they will be very versatile. i know they can be very effective, i've known people who use them for coral growth, i just need to dial in the proper amount of lighting for plant growth and discus happiness.
any suggestions on lighting ideas would be great. i plan on insulating the tank as much as possible, mostly via an insulated canopy, so i'm concerned about how the lighting i chose might hold up under very high humidity.
my next concern is that i want to house a breeding colony of cherry shrimp and scuds in the sump. though i've never had scuds before so i'd have to do some more reading on them. the little i did a few years back suggested that they will eat young cherry shrimp and plants. anyway, my concern is with the return pump. my plan is to just wall off the end of the sump tank with some sort of screen mesh, but i haven't decided what would be best for this purpose. i would like it not to trap too much detritus, but at the same time not let baby shrimp through. i might have to just give in and turn it into one big mechanical filter.
and i guess lastly, i've never tanks at discus temperatures for long periods of time before, and usually my plants do very poorly when it gets above 80, even amazon swords. so if anyone has any suggestions for fast growing filter plants, such as water sprite or pennywort that will thrive in warm waters please let me know.
oh, almost forgot the most important part, lol, bioload will be a group of 6-8 discus that i will sell off till i have 2 pairs, so 4 total, i was thinking a mormyrid too since i could never have one before, and a freshwater stingray if i can find one. probably reticulated do to the small width of the tank. i've never needed algae eaters before, but i am partial to plecos, so i might have a pair of bristle noses too, but i kind of consider them just excess bioload.
i'll probably add to that list with a few others down the road, but i cant think of anything i really care about right now. my passion and experience has always been micro fish, but with the ray, those wouldn't be great candidates. though if i don't get the ray, then there will defiantly be a few species of appistos in there
lastly, how do i do a long term build thread? do i just start it like a regular thread, or is it something different?