Setting up a low TDS aquarium

[Joshaeus]

Hi everyone! LONG time no post. This isn't specifically a dwarf cichlid question (inasmuch as my ten gallon tanks are likely too small for apistos or any other dwarf cichlids with the possible exception of some shell dwellers), but you guys have experience with soft water tanks and I thought this forum would thus be a good source of info for me. I have had a rough year with my tanks...my normally hard tap water suddenly began coming out quite soft, causing PH crashes (PH of 6, maybe a little less), the filters stopped working as a result (ammonia and nitrite started climbing in the afflicted tanks), and my tanks suffered a disease outbreak that wiped out many of my fish. I currently have no fish (we were going to move until recently, so I rehomed the rest), but I am considering turning all my tanks (two tens, one of them likely a growout/spawning tank, and a five gallon QT) into soft water tanks with low TDS. I've kept tanks like that before, but want your thoughts as to how to go about doing it...for example;
1, what TDS should I be shooting for? Is it possible to go too low?
2, how often (and how much) should I perform water changes on such tanks, inasmuch as nitrate will most likely not accumulate (at least not for a very long time...I've heard there are some VERY slow growing archaea ammonia oxidizers in acidic water, at least in theory) and ammonia is practically non toxic at such low PH levels?
3, how soon can I add fish after setup? I was going to add a lot of leaves and some driftwood.
4, have some suggestions for fish for these tanks? I'd love a two species setup in the main display, perhaps a small display fish (likely an anabantoid) and a small tetra, but I can keep it to a species tank if a ten is too small for two species. I'd move the fish to the second ten to breed them. I've consistently had bad luck with cichlids, so even if some soft water species would be comfortable in a ten with a lot of cover I am hesitant to try them.
5, have any good suggestions for submerged plants? I've not had great luck with submerged plants in the past (I primarily work with floating plants and emersed houseplants these days), but would love to give them another try.
6, any other thoughts?

Thanks My main fish forum burned me during my disease crisis in my tanks, so I don't feel comfortable using it anymore.

 

[anewbie]

The question around target tds depends upon the target species. Some species of fishes require mineral in the water others do not and prefer very little to none (esp if breeding).

The typical rules for cycling exist - though if you manage to get very low ph then the rules change a bit. I cheat and use seasoned sponge filters from another aquarium and monitor ammonia daily the first week doing larger water changes and adding a few drops of sachem prime (which claim some neutralization effect of ammonia). While some of my aquariums drift to below ph 5.5 over time very few start there though in truth i don't actually measure it.

Some cichilds enjoy hard water so again it depends on species - the biggest issue is that cichilds can have some aggression esp if breeding - so it is learning what type of aggresion your species has under what situation and managing it. Some species will be territorial (aggressive) even if a single one is kept and others will more or less live in harmony in a group.

There are quite a few small cichilds you can keep in a 10 - my favorite are a. pucallpaensis. A rather inexpensive nice little fish - they do have some aggression but m/f aggression is relatively minor.

As for size of water changes - different people say differen tthings - i change between 30% and 60% weekly it might be good it might be bad but it is what i do.