Hi,

I've had my 160 L tank set up for around 4 years now and always seem to be scraping the green spot algae from the glass.. it makes my tank maintenance more a chore than it should be!

you can see it on the glass in the photo but it's worse on the back glass which is harder to get to because its a hooded tank.

my water is otherwise clear and I don't actually have a greenwater problem.

The tank does not get any direct sunlight , and the lights are only on from late afternoon till evening.

I know about avoiding algae by not overfeeding and keeping up the water changes but it's an ongoing battle.

Would a UV sterilser help with general alage that grows on glass and ornaments and plants or is it really only good for green water?

Was also thinking about excel flourish, however I only have mostly slow growing java fern , quite a bit of it though., a little windelov, and a single indian fern which is tall and spindly and ugly - not growing nice and bushy.

if a UV sterilser/purifer would help, then the model I was thinking of is a 9W Blue Planet Uview purifer.

Do these need to go all the time as I wouldn't want to starve my butterfly pleco though he does get courgettes.

Any ideas how long a bulb lasts?

I've had otos but they don't seem to touch the green spot algae.

Used according to manufacturer's recommendations.

Would a UV sterilser help with general alage that grows on glass and ornaments and plants

No.

or is it really only good for green water?

Yes.

It has been found to be slightly effective in marine tanks in making proteins more easy to skim out of the water, which is basically irrelevant.

You could ignore the manufacturer's recommendations, remove the UV lamp from its housing and wave it over the algae. This however would result in severe burns, blindness, cataracts, tumors and death.

Of the available options I suggest spending the cost of the UV steriliser on bourbon and coke to be taken orally while looking at the tank and not giving a crap about a little bit of algae.

I had an 18W one on a 110L tank, no green water but lots of other algae.

ok, thanks guys - i won't waste my money on it

As above - the only thing the uv filter works on is free floating organisms which pass through the sleeve.

I have been told that if you have to have an algae the green spot on the glass is the better one as it shows your tank is close to being in balance. The only way to get rid of that is elbow grease - a credit card works great.