Hi all, i have had a big problem with hairy algae lately, it has only developed in the past couple of months, i have heard that siamese flying fox fish can get rid of it quite well and i hope to be buying a couple when i can, but i would like your own opinions
Thanks

James

are we talking black hair algae or green hair algae as both have very different causes and fixes.

I assume as you mention the siamensis that you are refering to the black hair algae or brush algae. Massive pain! I have recently removed all of the old substrate and plants and restarted my 4ft display tank because of it!!

So, why is it there? Well, two main reasons and the 'experts' cant even decide on which it is. Personally, i have gone with eliminating both and its all dying off The first reason is Phosphate. high phospahte levels will induce this algae to grow. I know this because my phosphate levels were off the chart high and this is the black algae's prime source of food, its a phosphate eater. Get a test kit for phosphate and see what your levels are. As you mentioned in another topic, you have a planted tank, you dont want it at zero, but less that one ppm for sure!

the second cause is fluctuating CO2 levels. Now, before you get freaked out, Im not going to get all chemisty on you. but very simply. CO2 (carbon dioxide) + H2O (water) = Carbonic Acid (H2CO3). this is what your plants are using to photosynthesise. Now, all tanks have carbonic acid in the water as a cencentration that is very low (4ppm). this simply comes from the air, just like the air that we breate has some CO2 in it. Unfortuantly, tap water is very high in carbonic acid, mine is upwards of 30ppm. So when you do a water change the carbonic acid levels jump, then as the CO2 bubbles out of soultion (those little bubbles you see on the side of the tank after a water change, or a coke bottle after you open it) the concentration drops. this fluctuation is the other main cause of Black algae.

Righto, so now we know what causes it, how do we get rid of it? well, first step to lower the phosphate levels in the tank. If the levels are high you need to figure out where they are coming from. There are two main sources of phosphate in a tank. The tap water you use to fill it or decaying plant matter. if its plant matter a clean up will do the trick. If it is your tap water then you are in a bit of trouble, like me. Test the tap water and if there is phosphate in it you need to employ something to remove it. THere are lots of chemicals to do this, Mostly, these go in the filter and chemically absorb it over time. Things like phoszorb work well. if you are going to use these types of things then ask on here for their propper use as incorrect use can be messy!

the second thing is getting rid of that fluctuation of CO2 levels. Now, I take it that you dont have a CO2 system on your tank, which makes this a lot easier. Instead of draining the water and then refilling direct from the tap you need to prepare the water beforehand. Strictly speaking we should all do this, but ...well most of us are lazy! take the tap water and put it in a bucket with an airstone. leave that for 24hrs with the airstone running hard. This will force all of the CO2 out of the water, meaning that when you add the new water to the tank it will have the same CO2 as the tank water, no variations, no more black algae

Also, the black algae can take some time to die, especially if you were like me and it had really taken hold, growing in thick mats on the glass etc. Use a razor blade to clean it off the glass and suck it out. then take your plants and rocks that have it on them and give them a 5 second bath is a solution of 3 parts bleach/7 parts water. This will kill the algae but not the plants as long as you give them a good rince afterwards. this will get rid of the algae in the tank and hopefully stop it from coming back again.

WOW, that is some incredible information, thanks Doug, you are correct about the black algae, i will try to get hold of a phosphate tester and depending on the problem, will follow your advice.
Thanks very much!

just a quick update, i haven't done a water change for a while, it is over due but the algae has started to die off but only on the glass, it is still thriving (annoyingly) on rocks.

Does this mean that it is the CO2 levels helping the algae?

Thanks

James

most likely, try bubbling the water for 24hrs before you do the water change...or boil it, then let it cool (obviously).

Thanks Doug

i am not sure when i am going to go the the LFS so won't be able to get an air stone, i shall try boiling the water, any ideas for how long?

Brilliant explanation Doug..Best one I've ever seen..No wonder I'm a Doug addict :

Im blushing

In terms of boiling it I would boil it for a few minutes. you will never get it all out so a few minutes, then the time to cool down will help out a lot.

OK, i have never found a site quite like this with so much information!

Thanks

James