Planted Tank Obsessed
Join Date: May 2015
Location: Central Michigan
Check out Bartohogs listings in the for sale section. Awesome selection, reasonable prices, good shipping, I've always been treated well when going through him. 99% of his plants are submersed growth as well.
Another good source I use is plantedaquariumscentral.com but most of her plants are not submersed grown. I've had great luck with potted carpet plants from her (dwarf hair grass, dwarf baby tears, and Monte Carlo. The first two were grown in high light and co2. Dwarf hair grass will work in a non co2 low light tank but will grow at a snails pace and take forever to carpet).
I'm a sucker for a nice patch of Anubias Nana Petite. It looks great it all aquarium sizes and requires only ambient light to stay alive. Downoi is another good low light, undemanding plant that doesn't get very big. I'm becoming a big fan of Monte Carlo carpets. I have some in my 7.5g cube (5g's of water), unheated, no co2, and the only issues I have is cyano from never doing water changes (not the tanks fault). It doesn't require a lot of light or any co2 to cover the substrate but it may take longer than a tank running those things.
It also wouldn't hurt to dose .5-1ml of seachem excel every other day or weekly mostly acting an algaecide but weekly 50% water changes should really cover any algae or water chemistry issues.