I have a continuous problem with brown algae in my 200 litre tank. The problem has been ongoing for 6 months and nothing I do seems to be able to control it. It fills the spray bar and pipes, slows down the canister filter flow, and just looks ugly. I've bought a UV steriliser, and no noticeable effect. I've taken the rocks out and scrubbed them, changed the pipes and spraybar (even bought a new cannister filter) but nothing seems to have any effect.

I have had some health problems with some of my fish over this period and have used Melafix and Pimafix in the tank quite a bit on and off. Could too much use of Melafix and Pimafix have done something to upset the eco-system in the water, therefore resulting in the over growth of brown algae?

The tank is an established tank (18 months old) so its not as a result of a new tank.

Can anybody suggest anything? I've read online about people using Maracyn 2 antibiotics to treat BGA in a
aqauriums. Would this work for brown algae?

The meds in the tank will definitely have upset the balance in the tank, so give it some time to settle again. Do you have plants in there? Plants soak up the nutrients that algae use so adding more plants should help to out-compete the algae.

Do you use activated carbon in your filter? I used to, and had a lot of brown algea too. But I took it out to use some meds before Christmas and didn't put it back in, and the difference in remarkable. Hardly any brown algae at all now, and I don't think I'll be adding the carbon back any time soon.

Woah there with the antibiotics they are usually not necessary for getting rid of algae, not even sure if they would work on brown algae. What are your water readings, specifically the nitrAte and phosphate? How heavily planted is the tank and how long are the lights on for?

Check your tap water phosphate levels Brendan.

My well established tank had an outbreak of this muck about 3 months ago for about 2 weeks until I realised I'd just forgotten to replace the phosphate remover (all used up) when I did tank maintenance. Seachem phosphate remover in a little baggy in the filter works well (phosban/rowaphos are 2 other brands). Lasts for a month or two (perhaps more) depending on your water levels.

Phosphate should ideally be low around 0 to 0.2, my usual tap water often has readings of 5, hence the problem. You can get tap water phosphate kits (via the API range on Ebay) very cheap.

UV only deals with green water and certain pathogens, not brown algae. HTH

i had a simular prob, stripped all plants out scrubbed rocks and wood, then got a timer for the lights- approx 4hrs on 2 off then 4hrs on i also reduced feed by quite a bit, then re-planted.all has been well since. good luck.

My nitrate readings are about 20, so pretty decent really. I don't know what my phosphate readings are, but I do use Rowaphos and change it every few months. I don't use carbon. The tank has plenty of Elodea in it and some moss balls. The lights are on a timer (on for 4 hours, off for 2 hours, on for 2 hours, off for 2 hours, on for 4 hours, off for 10 hours) I have now a 24W UV steriliser in the tank now.

What else can I do?

I'd still suggest a phosphate test kit really. Without knowing how much you have in the tap/tank water, it's hard to know when to replace the phosphate remover. Every 2 months may not be enough, if this is the trigger.

I would suggest using carbon in your filter for a while to remove old medicine and fish urine which incidentally can lower ph which you should check.

Hi dan just to clarify, Brendan has run carbon already after the meds and his pH is 7.5 as other posts confirm

You're not far from me Brendan so I'd guess your tap water phosphate is sky high like mine is ...