First off take the atinics off. The spectrum of light they give off in freshwater is only able to be used by algae. Then turn your lights off for at least one day and don't feed the tank. Next run your lights 6 hours only until the algae is gone. It would be even better to run them 3 hours on 2 off then another 3 on. Many algae prefer long light periods and by breaking the photoperiod up it makes it harder for algae to utilize the light.
Next keep using only 2 bulbs of lighting until after it's gone AND you start regularly dosing a liquid carbon or CO2. In a 55g tank DIY CO2 isn't going to be effective unless you run a lot of bottles.
What ferts do you use and how often? The higher the light the more the plants need in CO2 or liquid carbon and more ferts. If you run a high light tank you need to be using CO2 or liquid carbon and a full macro- micro fert dosing by using dry ferts and dosing either PPS-Pro or El regime all in the correct amounts.
You need to clean the glass, then do a 50% WC. Leave the lights off for a full night, day, then night. The following morning spot treat some of the algae by pulling up 3ml of Hydrogen Peroxide 3% for every 10g of tank water in a syringe (that would be 15ml of Peroxide) and squirt it slowly very close to the algae on the plants. You need to turn your filters and lights off before doing this and leave them off 20 minutes after treating the plants. You have a lot of algae so you are going to have to treat an area everyday until you get all the plants treated.
Next up your Excel (or whatever liquid carbon your using) to 25ml daily. Yes it is safe.
Continue your daily spot treating until you get all your plants treated and then start doing a 50% WC weekly. Do you know your nitrate and phosphate readings? Nitrates should be between 10-20ppm and phosphates .5-2ppm. You have to monitor your readings as you don't want excess nutrients in the water.
It is going to take time but this is what you need to do to get your tank balanced. You have more than one kind of algae.
Next keep using only 2 bulbs of lighting until after it's gone AND you start regularly dosing a liquid carbon or CO2. In a 55g tank DIY CO2 isn't going to be effective unless you run a lot of bottles.
What ferts do you use and how often? The higher the light the more the plants need in CO2 or liquid carbon and more ferts. If you run a high light tank you need to be using CO2 or liquid carbon and a full macro- micro fert dosing by using dry ferts and dosing either PPS-Pro or El regime all in the correct amounts.
You need to clean the glass, then do a 50% WC. Leave the lights off for a full night, day, then night. The following morning spot treat some of the algae by pulling up 3ml of Hydrogen Peroxide 3% for every 10g of tank water in a syringe (that would be 15ml of Peroxide) and squirt it slowly very close to the algae on the plants. You need to turn your filters and lights off before doing this and leave them off 20 minutes after treating the plants. You have a lot of algae so you are going to have to treat an area everyday until you get all the plants treated.
Next up your Excel (or whatever liquid carbon your using) to 25ml daily. Yes it is safe.
Continue your daily spot treating until you get all your plants treated and then start doing a 50% WC weekly. Do you know your nitrate and phosphate readings? Nitrates should be between 10-20ppm and phosphates .5-2ppm. You have to monitor your readings as you don't want excess nutrients in the water.
It is going to take time but this is what you need to do to get your tank balanced. You have more than one kind of algae.