I'd do a couple of big water changes to get the nitrates down. From what I've seen in my own tanks, when the water is too rich, the plants quit growing and the algae takes off.
You said it yourself with the above statement. (Vortex with more co2), just remember the old adage: "If it aint broke, don't fix it".:thumbsup: I would go back to what you already had since it was working just fine, after doing the above water change mentioned things should return to normal eventually, but if the algae is a problem just remove all you can find on the glass and ornaments/ heater/ filtertubes etc., and if you do not already have a algae eating crew get some shrimps, MTS snails, and 1 single bristlenose to eat the stuff up.I did add another DIY co2 and hooked up all 3 to the power head. But I modified the power head and made a vortex. This is when all the trouble started.