What causes red algae?

[67Stang]

OK, I'm noticing the start of some red algae in my 200gal reef tank. the tank has two metal halide pendants on 10hrs/day, 200lbs live rock, 4" DSB, water quality is perfect.

I'm not currently using RO water and figure this to be my problem.

Is this the only cause of red algae?

The problem is not too bad yet, what can I do to get rid of it?

thanks
Bruce

 

[pez]

Bruce,

I assume you are referring to cynobacteria, or slime algae? It has many causes and most of them relate to poor water quality. Despite the appearance of everything being OK in your system, the algae has found conditions it likes. Those are generally (very generally), poor source water, high phosphates, high nitrates, low alkalinity, wrong spectrum lamps or old lamps, over feeding, and excessively high nutrient load. There are probably more and some of these might not be your root cause.

Many of these things are coupled. A lot of fish usually leads to overfeeding, a phosphate problem, and poor water quality.

Please remember there is *no* magic bullet here. Cyno is a very difficult beast to combat once it gets a foot hold. Anyone who tells you to use antibiotics to kill it is practicing a very, very bad habit. It will kill the algae, and it will come back because the root of the problem has not been eliminated. There are cases where it never comes back, but they are in the minority.

There have been reports of cyno problems with new DSBs, but they subside after the sand matures.

If you could elaborate on how you feed, the inhabitants of your tank, the type of supplements you use, the type of lighting, how long the tank has been set up, etc., we might be able to help more.

As a note, I'd point to the source water first, regardless of any of the above information. Get an RO unit, you will not regret it.

-Tom

 

[AnotherGoldenTeapot]

Cyano is common if you have too much phosphate in your water. Nitrate levels are not important.

Cyano grows happily under all lighting - that's not the cause of your problem.

Without switching to using RO water it's going to be tough to beat it - probably impossible.

You also have the problem of how to get rid of the phospahte already in your tank. I'd use a phosphate sponge myself.

In this circumstance it's probably not ideal to use an antibiotic as it sounds like the cause of your problem is your water. If the problem becomes chronic (things dying because they are being smothered) then you might choose to treat with an antibiotic to buy you a few weeks to fix the underlying cause of the problem.

You need to get on top of this problem fast - it can get out of hand amazingly quickly.

I must say that anyone who ignores the possibility of ever using an antibiotics is a fool. You should always use the best treatment for the circumstances.

Cyano bacteria will only recur after treatment with an antibiotic if you continue to maintain an environment where it can get a foot hold. If you've fixed the underlying problem then it won't recur.

This topic comes up several times a week, so if you search the threads for the last copuple of months you'll find heaps of ideas on how to fix the problem.

 

[donmack]

Am I seeing red slime?

My tank has been up for a 6 weeks with live rock.

Filled with tap water (stupid, looking for a RO/DI unit now.

125G under 700W of VHO Actnic and ultrasun mix.

Readings appear normal.

What I am seeing is small pathes on rock and DSB that look like red velvet.