Green Spot Algae Problem

[slowcountry]

I have had numerous problems attempting to grow live plants in my 55 gallon display tank. The current problem that plagues me is green spot algae. It grows on the horizontal leaves of my plants and they stop growing. The leaves eventually die off.

I have 3 sword plants of some variation, they are approximately 9 - 10" tall. The leaves that grow almost vertical have little to no algae on them and are quite content. However the leaves that tend to bend over, have the algae on them, especially towards the top of the leaves.

I have 12 or so small plants, that resemble 'crab grass' that send out runners and grow new sprouts. These poor guys only get a couple inches tall and start to succumb to the algae.

The gravel in the tank also has some of this algae growth and a very little bit is present on the tank's glass.

I fertilize every couple of weeks with Sera Florenette A and twice a week with Flourish Trace. My water has a high pH 8.5 and is hard. I do 20% water changes weekly. I do not have any form of CO2 injection. The tank has a Aqueon 55 HOB filter. I had also run an additional power head for a couple of months to see if this would help, to no avail. It just seemed to #101## my fish off and blow their food around at feeding time. I de-stocked my tank down to a total of 25 community fish, guppies, sword tails, and neon tetras. I have a Cloallife dual T5 light with one 54 watt bulb and one 28 watt bulb installed for a total of 1.49WPG. Both bulbs are 6700K lamps. I leave the lights on for about 6 to 8 hours per day.

I would like to know if I have too much / little watts per gallon, to long / short lighting period etc. I believe my plants would do quite well if I could figure out what is keeping the green spot algae around. It is frustrating to the point where I don't even want to mess with live plants.

I appreciate any suggestions that I receive!

 

[RadaR]

You have algae because your plants are hungry. They cannot be expected to grow if they aren't getting the food they need. Therefore they begin to decay inside, uncontrollably leching out very low levels of ammonia that aren't harmful to fish, but are high enough to cause algae blooms.
Green spot algae is due to either low phosphate levels or low CO2 levels.

In short, the lighting levels you have are too high compared with what you are dosing in the tank.

Which powerhead did you use? Some aren't good and only send out jets of water that disturb fish. Whereas there are other powerheads that provide very good circulation and flow by moving bodies of water instead of single jets. Good powerheads include Koralias and Vortechs.

Remove any algae via scraping or pruning. Perform a 50% water change and siphon out any decaying matter in the substrate and/or filter.
Keep the lighting levels at 8 hours a day.
Dose 10ml of Tropica Plant Nutrition+ every other day. Dose 10ml Easylife Easycarbo everyday.
TPN+ contains all the micro and macro nutrients the plants need. Easylife Easycarbo is a form of liquid carbon which acts as a CO2 alternative in low light tanks.
Continue to dose these, perform 30-50% water changes weekly, keep the filter floss clean and provide good flow.
It's a good idea to fill the tank up with lots of fast growing plants as well.

Alternatively you could just take out the 28W bulb and keep the 55W bulb. This would lower your light levels and therefore the plants wouldn't demand so much nutrients and CO2. You could then rely on your fish to provide the nutrients they need and rely on respiration to account for the CO2 levels. Don't dose Easycarbo. Just to make sure there are enough nutrients, you could dose some TPN+ at the start of each week. Heavy planting is still advised as is good flow. The trick with this technique though is to not do water changes. This is because tap water contains quite good levels of dissolved CO2 and if you were to do a water change, that would dramatically change the CO2 levels in the tank. The fish wouldn't mind, but the plants have become used to low-medium levels of CO2. This sudden change would give algae the upper hand. After all, they are one of the most adaptive forms of life on this planet.
This method does needlessly worry some people however it is a good method. The filters and plants ensure that water quality is maintained highly. I'm currently doing this on my 125litre tank with good results so far.