I know when i used to have the plants healthy i would only do small water changes every few weeks or they would get upset. I bought some dechlorinator yesterday and did a water change using my municipal water, the plants seem to have greened up a little bit. I have been using rain water for ages but i used to use water from my municipal when i had plants. As for diy co2 i really want to keep my 5 gal moderately low tech like it used to be. I was thinking of using excel instead? I've brought my lighting up to a 18w 1100 lumen 6500k bulb. The plants are directly under it and it looks fairly bright. Also as for stocking i thought i would be already slightly over stocked for a 5?