Green Algae Covers Glass Within A Day!

[Dazzi]

Hi,
I recently set up my nano tank about a month ago. I used to have a 40 gal a few years back so have a lot of experience. Any way the tank is an AquaQube 40l with a 70w metal halide 10000k, fluval filter and a skimmer. It has a few lbs of live rock in atm and the water specs are good: SG 1.026, PH 8.0, Ammonia 0, Nitrite 0, Nitrate 0, Phosphate 0. Im using RO water with premixed salt from the local fish shop. Everything was going great for about 2 weeks but one day I came home from work and the whole tank went green. It was as if someone turned the algae on.

I know this might be due to the tank cycling but isn't that kind of algae brown? This is a lime green that im getting. When the lights come on it only takes an hour to get a light covering on the glass but after a whole day you can barely see through at all! I have a suspicion that the RO water im getting may be loaded with silicate so im going to get a test kit for this and see.

 

[ox5477]

I usually have to scrape daily to remove a film of red algae. It may be the same family of algae, just a different color. I have some phosphates spikes here and there due to the flake I give my wrasses every once in a while, but even using a phosx, I still get the consistant layer of red film..

 

[Dazzi]

The thing is, my tank doesn't have any fish in it so I don't need to put fish food in. The Nitrate & Phosphate both come out a 0.... Im really baffled at why the algae is growing so fast. When I had my 40gal marine tank I used tap water when I first filled it up and tap was for water changes and top offs. The algae was never as bad as this one. The Nitrate was 30ppm and the phosphate was 5ppm.... yet now with the Nano I get 0 on both but its worse?!

 

[Dorkhedeos]

Try increasing the flow, if it is what i think it is, its not algae. Slime algae is actually cyanobacteria, and if you increase the flow it should go away.

 

[Underwurlde]

Tape up your substrate too.

What am I on about?

In otherwords, DON'T allow any light get to the sides of your substrate, use black electrical tape and cover it up on the outside of your tank.

Andy

 

[Dazzi]

Try increasing the flow, if it is what i think it is, its not algae. Slime algae is actually cyanobacteria, and if you increase the flow it should go away.

Hmmm, thats a point. Where there is direct flow the algae doesn't grow so much - like a light coating but say at the otherside of the tank it gets thick. I will increase the flow and see how it goes.

Thanks

 

[Dazzi]

This is certainly not slime algae after some detective work. The algae seems powdery and doesn't grow as strong in the flow of the power head. I have no idea what is going on here... the algae has no reason to grown considering my Nitrate is 0 and phosphate is 0.

 

[dilbert]

Some water test kits are not that sensitive as others. With already two API nitrate tests - one bought in the UK and one bought in the US - I am getting always zero when Dry-Tab or Salifert measure the whole scale from 1 to 30 ppm on the same water.

I haven't seen this with phosphate tests but most of them have almost identical colours on their charts. I bought the D-Deltec phosphate test. It's not the real Merck test (that costs £ 100) but it mentions Merck on the box and costs £ 30. This test is quite good with two vials (one is for comparison only), a styrofoam comparator block and a decent colour chart with reasonable colours.

Here are a few links to the Merck and D-Deltec tests:

¦Merck PO4 test kit £99
¦Salifert Organics test kit £11
¦www.angliaaquatics.com
¦
¦D&D Merck PO4 test kit £28
¦www.aquatics-online.co.uk
¦
¦D&D Merck PO4 test kit £30
¦Salifert Organics test kit £11
¦www.fantasea.co.uk

BTW, that's from my notes and the dissolved organics test from Salifert is also quite interesting. The dissolved organics in my nano are five times as high as they should be. (I already assumed this but now I know it.)

That's for the testing part of your problem. But for algae the limiting stuff is more phosphates than nitrates.

To the phosphates in the tap water from Yorkshire Water. Our tap water has about 0.1 ppm phosphates. So, in a tank with fish the most phosphates come from feeding rather than from tap water.

I presume that your phosphates in your nano tank without fish and feeding come from the substrate. Even if you wash it consecutively before you add it to the tank (even that one where it says that rinsing is not needed) you always get some phosphates in it. That leads to the first brown algae outbreak normally and when all phosphates are consumed and you don't add anymore you're done , normally.

Adjusting the flow is quite difficult as you often have corals or other animals that don't want the strongest flow and on the sandbed it's diificult to have a good stream without sandstorms. A bare bottom tank would there be an advantage.

I simply clean and harvest that stuff: red slime, hair algae, overall. I mean I got also bubble algae and Aiptasia, so the normal algae are not too much of a hassle.

Taking them out instead of letting eat them by cleaners has the advantage that the cleaners won't produce detritus from that stuff. Simply taking it out and it's gone. An easy way to remove nitrates and phosphates from the tank.
I got already four Maxi-Jets (that heat up nano to the maximum), so there are only a few spots where all those nuissance algae accumulate, and it's a nano, not too big for that kind of work.

 

[SkiFletch]

...the algae has no reason to grown considering my Nitrate is 0 and phosphate is 0.

A common misconception. Remember, our test kits only measure free nutrients in the water column. If an algae is groing sufficiently fast enough, it can consume the nutrients you are trying to measure as fast as they become avialable. So the test kit shows 0ppm but the growth of the algae indicates a nutrient problem...

 

[dilbert]

I presume that your phosphates in your nano tank without fish and feeding come from the substrate. Even if you wash it consecutively before you add it to the tank (even that one where it says that rinsing is not needed) you always get some phosphates in it. That leads to the first brown algae outbreak normally and when all phosphates are consumed and you don't add anymore you're done , normally.

Just for the sake of truth:

That what I've written there is not complete nonsense but pure speculation and surely only half-true. Silica play an important role when adding new substrate to the tank.
So, as long as no one knows better simply scratch this paragraph.

The only thing I can say is that my newly set-up pico tank also had 0.45 mg/l phosphates in it when it had run about two weeks with only a piece of live rock and a Chaetomorpha ball and two visible hitchhikers in it: a small tubeworm and a tiny crab (maybe a Gorilla crab).

There were only a few brown algae on the glass visible and red slime that came with a "seeded" Chaetomorpha ball grow only a little and then stopped but 0.45 mg/l phosphates "from nothing" is quite a big figure.