[WillieM96]

I know this question has been asked ad nauseum but here comes my version of the question. Here's my setup:
50 gallon aquarium
50 pounds of live rock
1 inch aragonite sand bed
T-5 lighting
Remora Pro skimmer with mag-3 pump
Ammonia, nitrite, nitrate, phosphate all reading at zero
Livestock: hermit crabs, snails, 1 emerald crab, and 2 fire fish
has been up and running for a month and a half.
5 gallon water changes every 1-2 weeks.

So, I went away for the weekend last week, had a neighbor feed the fish for me, when I came back there was a ton of slime algae growing on the sand (nowhere else). I removed it by hand and it keeps growing back. Finally, I did a major cleaning in the tank, cleaned out all the filters and picked off all the stringy slime algae from the sand. I woke up this morning and a decent amount of slime algae has already grown back on the sand. WTF?? With no light can it grow back that quickly?? I know I've been over feeding the fish and I know that is contributing to the problem but should this stuff be growing that quickly???

[Ninong]

Originally Posted by WillieM96

I woke up this morning and a decent amount of slime algae has already grown back on the sand. With no light can it grow back that quickly??

It's grows very quickly because it's bacteria, not algae. Cyanobacteria!

Remove as much as possible by hand every day if it bothers you or if it seems to be taking over. It's photosynthetic, so lighting does affect it. Your lighting should be fine since you say it's T5 and this is a brand new setup. What's your total lighting arrangement? How many lamps, what wattage and what Kelvin rating?

Cyanobacteria is nitrogen limited. It's a photosynthetic bacteria that has the ability to fix nitrogen. Quite often it will show up about this time in the cycle of a new aquarium. It's certainly not unexpected. I didn't get any in my cycle but that was unusual.

All you can do is watch your nutrient levels and wait it out. In the meantime, aiming water current at the affected areas will break up the strands of cyanobacteria. Eventually good skimming, good light and normal maintenance will win out. That and the fact that as your tank matures and other forms of life grow, they will outcompete the cyanobacteria for resources -- both available space and available nutrients.

Cyanobacteria is nothing to get all worked up about. There are way too many variables to get into a discussion of all the possible causes but the fact that your tank is brand new is the major reason you are having this outbreak right now. Even experienced hobbyists with mature tanks with extremely low nitrogen levels can experience occasional problems with cyanobacteria. In those situations it is often brought on by degradation in the lighting -- shifting towards a part of the spectrum more conducive to cyanobacteria.

Cyanobacteria has been around for more than 3 billion years. You might say it's the most natural thing in the whole world.

[WillieM96]

As far as the lighting goes, I have the nova extreme fixture (4 bulbs) which came with 2 Slimpaq 460nm Actinic bulbs and 2 10000°K T-5 HO lamps. It's the 36" fixture and the bulbs are 39 watts each. I have the actinics on about 12 hours a day and the white lights on about 11 hours a day.

[dibenni]

What does this cyanobacteria look like?

I have a similar situation to Willie - although I have not yet tried to remove it. My tank is fairly new - almost four months - I have a few fish and some snails and crabs. All of my readings are fine. The other day I had some slimey (or it appears slimey, I haven't felt it) dark maroon algae-like substance on my sand. It has multiplied rapidly in 2-3 days and there is a good amount now covering my sand.

Do you think this is cyanobacteria and should I follow the steps above (ie. remove it by hand when there is too much and keep my water quality up and circulation strong and it will eventually go away)?

[Ninong]

Originally Posted by dibenni

What does this cyanobacteria look like?

I have a similar situation to Willie - although I have not yet tried to remove it. My tank is fairly new - almost four months - I have a few fish and some snails and crabs. All of my readings are fine. The other day I had some slimey (or it appears slimey, I haven't felt it) dark maroon algae-like substance on my sand. It has multiplied rapidly in 2-3 days and there is a good amount now covering my sand.

Do you think this is cyanobacteria and should I follow the steps above (ie. remove it by hand when there is too much and keep my water quality up and circulation strong and it will eventually go away)?

Sounds like cyano. Does it seem to increase after the lights are on for a couple of hours? In other words, does it seem like there is less of it early in the morning and then more of it after the lights are on for a little while?

What is your lighting? In particular, what is the Kelvin rating?

Things that will help:

Maintain your calcium around 450-475 ppm and your alkalinity in a range of 10-12 dKH. The alkalinity is the trick here but you will need to keep your calcium and alk in balance.

Direct water current at the problem areas and/or remove excess cyano manually.

Try to maintain nitrate levels as low as you can. Cyanobacteria is a photosynthetic bacteria with the ability to fix nitrogen. It is unique! In fact, it has its own phylum.

It will eventually go away on its own. It's not all that unusual for cyano to show up during the first few months after a tank has been set up but it is less common for it to be a problem in a mature, well-stocked tank.

If you run a search on this board using "cyanobacteria" as your search term, you will get a lot of hits.

[WillieM96]

I cleaned out my skimmer the other day and it's producing a ton of skimmate and since then, I haven't seen any significant growth. I guess I just needed to clean the darn thing out.

[dibenni]

Ninong, there is less of it during the morning and then it is back when I get home from work. My lighting is a Coralife fixture with 2 65W 10K fluorescent bulbs and Actinics.

It doesn't appear to be a big problem - its not like it is overtaking my tank. Just wanted to confirm that it wasn't something I should worry about. I will just let it run its course then and hopefully it will take care of itself.

[WillieM96]

Just to update- my cyano problem is just about gone. All I've done is continue with the maintenance, clean out the filters and not over feed and it's looking good now. I guess it was just a cycle thing.

[sihaya]

LOL Sounds like my tank right now. Mine's a little worse because I had to replace the whole sand bed (aquarium sprung a leak and had to replace the tank itself). Like you I'm just going to have to wait it out I guess.