[Jonny Rotten]

was going for low tek but the plants looked weak.2 weeks ago I doubled light,(2 t5ho in a crappy reflector) started dry dosing ferts,and excel.Plants now look healthy and Im happy with the growth speed.But Im getting bba and green hair algae.At this point the only reason I would add co2 is to combat algae.Is that my only option???Dropped lights to 8 hours a day also,anything less and whats the use of having a tank 55g

 

[Kathyy]

Trying reducing the strength of the light by either shading the tank with floaters or window screening material or raising the fixture. If you go back to the previous lighting and continue dosing a reduced amount you might be happier with the tank than using the double T5.

I haven't seen hair algae since I started using CO2 but BBA is an issue even with CO2's use.

 

[Jonny Rotten]

I have some floaters,1 light very low light,not nearly enough.Interesting with the bba.I thought co2 would solve that problem

 

[Hoppy]

The reason for CO2 is the plants needs. With more light the plants are driven to grow faster, but that requires more CO2 than the atmosphere can supply to the water. If the plants don't get their needed CO2 they don't grow as healthy as they should, and unhealthy plants lead to algae infestations.

BBA usually start growing on hardscape at the top of the tank, where the light intensity is the highest. That is one good reason for hanging a light a foot or so above the top of the tank - it reduces the intensity at the top of the tank.

Two T5HO bulbs, if driven to full HO power, can give you enough light that CO2 is essential even if the reflectors are poor.

 

[Jonny Rotten]

The reason for CO2 is the plants needs. With more light the plants are driven to grow faster, but that requires more CO2 than the atmosphere can supply to the water. If the plants don't get their needed CO2 they don't grow as healthy as they should, and unhealthy plants lead to algae infestations.

BBA usually start growing on hardscape at the top of the tank, where the light intensity is the highest. That is one good reason for hanging a light a foot or so above the top of the tank - it reduces the intensity at the top of the tank.

Two T5HO bulbs, if driven to full HO power, can give you enough light that CO2 is essential even if the reflectors are poor.

Thats the odd part.The BBA is on the lowest part of the plant,in the lowest part of the tank.All the new growth has none

 

[Hoppy]

BBA, and most other algae will go for the weakest, least healthy parts of the plants, which tend to be those at the bottom, old growth, farthest from the light. If the plants are running a bit short of nutrients or any one nutrient, they can sacrifice the lower growth, absorbing the nutrients from that part to keep the upper growth going good. And, finally, once BBA gets going good it is extremely difficult to completely get rid of it in the tank. I gave up using more than low medium light for good as a result of my futile efforts to get rid of BBA with higher light intensity.