For those who have lit a 10 gallon with CFLs, and all others. Question about algae.
This is one of my first posts here. I have had aquariums on and off for approximately the last 20 years. Mostly, I have had reef tanks which may be skewing my perception concerning how much light is "enough". Over the last several months, I have been working with a small planted aquarium. It's a 10 gallon that was previously home to a betta for about 4 years that I converted over to full planted. Essentially the problem I've had over the last month or so is that I have begun injecting CO2 and fertilizing; although I am getting very nice growth out of most of the plants, the older growth which once looked vibrant and healthy as started to grow algae and not look so great. Not covered in algae by any means, just not looking great.
The tank is fairly heavily planted with a variety of different species, including Bacopa, Hygrophila, S repens, Althernanthera reineckii, Monte Carlo, Ludwigia repens, Rotala rotundifolia, Anubias nana petit, and Crypt wendtii red. Some more demanding plants and some easier plants. It is a Dutch style and about 90% of the substrate is planted. Some more details about the tank are below:
I am lighting this tank with 2x13W 6500K CFLs. They are mounted vertically. I recently raised them up about 17ish inches off of the substrate last week, and although the new growth looks fantastic and is occurring quickly, I am still experiencing old growth looking not-fantastic after about a week. Not as bad of a decline as previous weeks though. Photo-period is 6 hours, which I also reduced from 8 hours last week.
I am using NilocG's Thrive, dosing 2 ml 3x per week (Monday, Wednesday, Friday). I then do a 50% water change weekly (Sunday) and restart the process. I do not dose with the pump top it comes with because it's extremely innacurate. I use a syringe to accurately dose 2 mL every other day. This should put me in the EI range for macros and micros.
I am using Burr740's tried and true DIY CO2 recipe. It works fantastically, and the DIY rig I built has been great with changing only one bottle weekly. On testing, tank water vs. degassed tank water, I am able to achieve a 1.4+ pH drop. My drop checker is constantly lime green. Additionally, the plants are always consistently pearling under the 2x13W CFLs. This makes me think my CO2 is in adequate range.
Seachem's Fluorite + Seachem Root tabs
Most recent parameters from log (06/03/18):
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: 40 ppm (just before water change)
GH: 10 dGH
KH: 6 dKH
So, I hope I've given enough information here to help you all help me figure out what my problem may be. I am open to any and all suggestions. As far as recent changes, on 06/03 I made a photo-period adjustment to 6 hours with the 2x 13W CFLs. Does this sound like too much light is the issue? How have those that have lit 10 gallon tanks with CFLs before done it? With smaller bulbs, or with this size? Finally, I should add that not all the plants are experiencing this. The worst are the S. repens. The ludwigia, Rotala are nearly unaffected and doing great, as is the Hygrophilia. Thank you for taking the time to read through this!