I have a 10 gallon that is heavily planted with flourite dark substrate, do not dose, lights are on and off all day for an hour at a time for a total of 6 hours, and the lights are the 24 inch oddysea's ;total of 72 watts. I am using DIY CO2 with double of the dosage with two bottles. So at first the drop checker reads yellow:high CO2: and then it comes down to green. I just started this 2 weeks ago before I noticed any bad aglae. Could this be the problem? Nothing else has changed. It has been going for 3 months. If I forgot anything please ask me, any help is better than nothing! Also, if nothing else I am having real thin, thinner than hair, strings of algae... Maybe they are connected? Noticed it about a month ago I think.... Thanks again!