I've had that plant underwater for nearly 2 months now without a problem, but the plan is to take it out. I'll probably just pot it and see if it survives like that. I don't really like it now. I don't know how to describe it, but it's very stiff, I'm probably going to replace it with some amazon swords which will move with the water. I was going to go to my LFS today after I was done with my GIS labs at school and probably get a dwarf gourami for my 10 gallon - since I just gave away my guppies and emerald catfish, leaving me with 2 peppered cories and an oto - and a couple of swords or some more val if they had anymore.
My DIY CO2 system for the 15 gallon is coming along fine. I've got the yeast, sugar, tubing, some 2L bottles. I'm just waiting for my dad and brother to finish off the soda so I can take the bottles.
I've tried to drink some of the soda, but I'm not a big soda drinker, not like I was when I was in my teens. I was going to use both the 2L bottles for 1 CO2 system. I was going to fill one up with the CO2 mixture, and connect it to an empty bottle, and then connect the empty bottle to the filter intake. This way, I can hopefully prevent a disaster in which my mixture makes its way into my tank, killing everything! I just hope i don't get some back-syphoning action from my tank. I just ruined the airpump I had in there by disconnecting it before taking it out. I was goin to take the airpump out, but I didn't want to mess it up - oh well. Live and learn.
I still have to research a recipe for the 5 gallon, I don't want to risk suffocating the fish in there by pumping in too much CO2.