Hello board! I'm new to your board, but have been keeping fish off and on for years. I'm about to make some significant changes to my setup and just want some input to make sure they are sound ideas and not going to come back to bite me in the butt (figuratively!) later. I guess i don't have specific questions, just want to lay out my plan and get some feedback.
The tank in question is an established, moderately planted (low light, lots of crypts, anubias, and java fern) 20 long with a pure flourite substrate. At the moment it's being filtered with an Eclipse hood which over the years i have come to despise for it's insufficient mechanical filtration, splashy waterfall biowheel and weak, poorly placed lighting (2@17W). For now i'm keeping the hood/lights as is, but i'm going to change the filtration. The tank is currently inhabited by nothing but a pair of Von Rio tetras and a colony of snails (pond snails & malaysian trumpets). The Von Rios are slated to be given to a friend for his community tank which will leave me with a blank slate.
Now, the 2 little tetras produce so little bioload that i'm fairly certain it has all been immediately absorbed by the plants, which show signs of nitrate deficiency, nitrate levels always test unreadable. So i'm considering the tank to be uncycled for the purposes of fish adding, and since i'm going to have no fish in it now is the perfect time to replace the filter and fishless cycle via ammonia. I often hear that fishless cycling in a planted tank is either A. useless (but that is always assuming high light, CO2, fast growing plants, which i don't have) or B. harmful to the plants (which i don't buy, having done it before). So, i plan to get a small canister filter (either the smallest Eheim ECCO or a Filstar, about the same price *Edit-got the Eheim*) and hope that i will be able to set that up without it interfering with the silly Eclipse hood. Then i'll fishless cycle by adding ammonia til i get 5ppm. That way, even though the plants will directly absorb some of the ammonia, there should be quite a bit left over to feed the bacterial colonies. I've done this before and it took about a week and didn't damage the plants at all. I've had much better results with keeping the fish alive by adding them all at once after a hard fishless cycle rather than the slow 2 at a time method which always ends up introducing disease since i have no QT tank and no room to set one up.
Then, for stocking, i'm using a surface area rule to account for the greater oxygen exchange of the 20L versus the 20 regular or tall which the old school inch per gallon doesn't. The formula i've seen is length x width for surface area (in my case, 360 sq inches), with newbies using only half and experienced aquarists using 3/4, i'm going with half personally which gives me 180, divide that by 6, and i'm left with 30 inches of adult length. So i'm thinking 5 cory cats, 8 Zebra danios, and a female shortfinned betta to keep the danios shoaling. I may drop the cories and get more danios. Any comments?
The tank in question is an established, moderately planted (low light, lots of crypts, anubias, and java fern) 20 long with a pure flourite substrate. At the moment it's being filtered with an Eclipse hood which over the years i have come to despise for it's insufficient mechanical filtration, splashy waterfall biowheel and weak, poorly placed lighting (2@17W). For now i'm keeping the hood/lights as is, but i'm going to change the filtration. The tank is currently inhabited by nothing but a pair of Von Rio tetras and a colony of snails (pond snails & malaysian trumpets). The Von Rios are slated to be given to a friend for his community tank which will leave me with a blank slate.
Now, the 2 little tetras produce so little bioload that i'm fairly certain it has all been immediately absorbed by the plants, which show signs of nitrate deficiency, nitrate levels always test unreadable. So i'm considering the tank to be uncycled for the purposes of fish adding, and since i'm going to have no fish in it now is the perfect time to replace the filter and fishless cycle via ammonia. I often hear that fishless cycling in a planted tank is either A. useless (but that is always assuming high light, CO2, fast growing plants, which i don't have) or B. harmful to the plants (which i don't buy, having done it before). So, i plan to get a small canister filter (either the smallest Eheim ECCO or a Filstar, about the same price *Edit-got the Eheim*) and hope that i will be able to set that up without it interfering with the silly Eclipse hood. Then i'll fishless cycle by adding ammonia til i get 5ppm. That way, even though the plants will directly absorb some of the ammonia, there should be quite a bit left over to feed the bacterial colonies. I've done this before and it took about a week and didn't damage the plants at all. I've had much better results with keeping the fish alive by adding them all at once after a hard fishless cycle rather than the slow 2 at a time method which always ends up introducing disease since i have no QT tank and no room to set one up.
Then, for stocking, i'm using a surface area rule to account for the greater oxygen exchange of the 20L versus the 20 regular or tall which the old school inch per gallon doesn't. The formula i've seen is length x width for surface area (in my case, 360 sq inches), with newbies using only half and experienced aquarists using 3/4, i'm going with half personally which gives me 180, divide that by 6, and i'm left with 30 inches of adult length. So i'm thinking 5 cory cats, 8 Zebra danios, and a female shortfinned betta to keep the danios shoaling. I may drop the cories and get more danios. Any comments?
I'm a bit worried that the straight fluorite substrate might be a little tough on their barbels though... I have considered adding some sand to the top...
) I have the flourite on bottom and either fine gravel or sand about 1 inch on top. works very well for all. 
