Planted Tank Enthusiast
Join Date: Jan 2013
Location: Reading, Pennsylvania
You can leave them floating as long as all your equipment is still functioning. They wont die, maybe just start to curl towards the light.
The pleco is completely up to you if you want to put it in your tank or not, i know as they grow some lose their algae eating ability, due to no being interested in it anymore.
As for plants....
- carpet - I would go with stargrass, dwarf sag, S. Repens or something along those lines. I have all three in my tanks and under a finnex planted plus all three grow fine. The higher the light the shorter the plants will stay. S Repens will need the tops trimmed I believe to keep it shorter but the other two work off of how high your lighting is. higher lighting shorter plants to get that carpet affect.
- moss - really any moss will do for this purpose, personal favorite of mine is christmas moss, but again any moss should work for covering up your foam and whatever else you have to cover.
- background - This again is all personal preference, If I were you I would go with ludwigia repens or maybe a rotala species. Both of these are easy to grow and arent too demanding. Now if you wanted something different you could go with jungle val, which is also and easy grower, but this will look completely different from the other two. Jungle val in my experience grows well and fast.
+1 on testing your water, good rule of thumb is planting your tank then letting it sit fish-less for two weeks or so to get your cycle going if not finished. After those two weeks then slowly acclimate your fish to the new tank.