I'm in the exact same boat as you. I could'nt afford pressurized CO2
when I started up my planted tank a month ago. At this point, it looks like it might be a while, so I'm going to build a DIY
yeast system for now.
Anyway, I have been dossing with excel for carbon, seeing how I don't have any CO2
set up. Heres what I have noticed.
My java moss, and stem plants such as ludwigia, cobomba etc... are pearling and doing great. Having to cut them back weekly (well not the moss, its a slow grower
The radican, marble leaf and amazon swords are not thriving, but they are obviously showing signs of new growth. The swords also have a vibrant green color, no brown or yellowing leaves after a month. Swords are also heavy root feeders, so I think the eco complete and ferts in the substrate are helping a lot.
My only problem is my micro swords used for foreground. They are slowly yellowing. They are very slowly showing signs of new growth, but dieing faster than it's growing. I'm not sure if 2.6 wpg
of lighting is'nt enough or lack of CO2
Keep in mind, this is my first planted tank, so I'm no expert by any means. IMO
if you have good lighting, filtration, substrate, ferts, water para's etc....... you should be able to keep most plants (depending on species and needs) until you can get a CO2
system. Just do frequent water test and adjust accordingly.
Just thought I would share my observations, seeing how we are in the same boat. Hope this helps