Your photo period is way too long. think of your light as a gas pedal. You are stepping on the gas pedal but it looks like your tank is running out of gas (co2). I would invest in a pressurized setup with a good solenoid and needle valve and reduce your photo period by three hours. also, continue with doing water changes maybe every other day and dose some ferts....feed your plants not just with light but with co2 macros and micros. It also looks like you planted your hc in clumps. I have had more success when planting smaller bunches of 2 to 3 stems together. When you clump them together like that the plants take longer to establish and you can experience some root degeneration. good luck.
Darn I checked out nilocg ad on sns and it looks like I have to turn on and off the co2 manually. I'm busy most the day so I can't be home to baby sit my tank
If you are looking for a reg with solenoid then perhaps you can checkout the aquatek mini. It's on amzaon with free two day shipping for prime members. It's a bit more expensive but it does have a solenoid that you can plug into a timer
Anything good setup has that initial cost, but in the long run its worth it. Like I said mine has been running with out a need to be touched for a year. I hated having to do the DIY mix and I can't say enough good things about the difference a real Co2 setup does.
This is the setup I purchased firs Regulator (Comes with free Co2 Diffuser so thats bonus):
I have been thinking about buying aquatek co2 regulator mini with 20oz co2 bottle for a few days now and it's driving me insane. Can anyone convince me why I should go with pressurize co2 instead of my DIY co2 for my 5.5 gallons? I don't want to spend $140 for something when I can get co2 into my tank for a few cents by just mixing sugar and yeast.
Also a DIY can't be stopped at night so it pumps into the tank even when lights are off and the plants can't absorb it.
I just run CO2 for a few hours a day- usually during my first photoperiod: 9am to 1pm. Then I just pull the airline off the top of the canister. It just vents out. I am sure my houseplants next to it are appreciative
I have a pincher valve on the airline and have it adjusted to 1bub per second in an acrylic ladder set up. I also half dose Excel a few times a week.
At night I drop an air stone in when lights go out.
Just received my aquatek co2 mini regulator and my 20z tank. Does anyone have the same problem I'm having? When I set the flow of co2 of how I want, in a few hours it decreases to almost nothing and I have to fine tune my knob again back up. Also will pressurize co2 help my baby tears grow better now since I have more co2 for my high light?