Algae problem on pool filter sand

[KINGMED]

I have a 55 gallon tank that I have had set up for around 8-9 months, it has about 2" of pool filter sand in it, 3 pieces of mopani drift wood and some feller stone. I do a regular 20-30 percent water change a week, and have notice in the last few months a algae bloom on the sand, it is dark...I guess maybe darkish greenish blue in color and when I do suck it out of the tank it seems to be almost crusty on top. I have noticed that the sand is getting this color under the sand also, this is not all over the tank only in spots. All the water chemistry is good, I had this same problem while living in Pa. and even there was unable to completely get rid of it, however the bristlenose pleco's helped a bit. My question for you all is could the mopani driftwood be causing this?, also I do not keep the light on very often only a few hours per day, and the water temperature is staying around 78 to 80 degrees. I'm not sure if I should syphon out the whole sand and start over or just replace it with gravel? I really like the sand idea and would hate the idea of transferring media, I would appreciate any advise to help get rid of the algae bloom, Thanks.

[Cliff]

Sounds like Cyanobacteria to me. Its not really a algae, but it is a form of bacteria. The below link could help

http://www.aquaticcommunity.com/aqua...ad.php?t=24570

[MandyK]

Blue green algae. More light time, will probablly fix this. I keep my light on about 9 hours a day, and dose with Excel to combat this stuff! Just a different name for what Cliff is referring to.

[KINGMED]

Where can I get excel?, does Petsmart or Petco carry this? I don't know if anyone knows but how does this stuff start, I only get it in my 55 gallon tank, never have gotten it in my smaller tanks.

[fishguy125]

I know it's a novel, but I found this very helpful.

http://www.who.intwater_sanitation_h...cyanchap12.pdf

[Lady Hobbs]

As Cliff said, this algae is a bacteria, not an algae so not too sure Excel will kill it. An antibiotic will but you may also loose your cycle.

[Lady Hobbs]

Fishguy........link not working for me but then..........I have that problem all the time here now since I switched to FireFox so not sure if it's my computer or your link.

Server not found
Firefox can't find the server at www.who.intwater_sanitation_health.

*sigh

[fishguy125]

Fishguy........link not working for me but then..........I have that problem all the time here now since I switched to FireFox so not sure if it's my computer or your link.

Server not found
Firefox can't find the server at www.who.intwater_sanitation_health.

*sigh

Ok, thanks for telling me. I will try reposting it :http://www.who.int/water_sanitation_...cyanchap12.pdf

[Cermet]

BGA is more often than not caused by incorrect water parameters and/or poor/too much lighting. Lets us know the water parameters (nitrates) and light age/color/wattage and duration. Until the issue causing it is cleared up, it will return after treatment. My guess is that your nitrates are too high ... .

[KINGMED]

Sorry for being gone so long, it's been crazy around the house the past few weeks. Today got the parameters checked at two different pet stores in the area and they both got the same exact readings. The Nitrites are 0, the Nitrates are 10, PH is 6.8, alkalinity is ideal (100), Hardness is 7.5. The tank was bought from a person off of craigslist in March 2008, haven't changed the bulb since then and he said he had the tank setup for 10 or so years so I really don't know how old the light is, duration of the light is very little mainly cause I thought the light was causing the algae growth...say when I do have it on maybe 6-8 hours and then a few days in between without it on at all. The light bulb is a 40 watt bulb, the set up is still very very nice...wood grain around the tank, and on the light which is a 4 footer and a wonderful wooden stand. Can I use a higher wattage bulb in one of the regular aquarium setups?
The Petco which is one of the places I got the water checked today said they have the same issue with the black algae growing in their rocks and they have to replace the rock every so often.
I was thinking it may be in the water, I leave presently in Wichita Falls Tx., we are in state 3 drought...lakes are loosing tons of water and I was wondering if the tap water may be causing this to happen. Thought about going to the grocery store where I can get the water out of the machine for .35 cents and do my water changes with this??? Also thought about adding salt to the tank but I don't know if this would help. My other option was to syphon out all the sand and replace it with new pool filter sand, re-boil the mopani driftwood and the feller stone, but I've tried this in Pennsylvania and it still didn't work. Was not able to check Phosphorus parameters of the tank because the pet stores that I got the water checked don't do this test.