UV Sterilizer for algae problems?

[twb716]

My girlfriend has a 29gal goldfish tank, and I have been helping her take care of it. It has all of a sudden started to grow A LOT of algae. The water has a greenish tint, and all of the tank decorations are covered. I have tried putting in some algae tablets, and we've even scrubbed the decorations by hand with no luck. I have also been doing pretty frequent water changes (3 per week @ 20%). There are only 4 fancy gf in the tank. UV sterilizer to keep things under control? Any thoughts/comments will be greatly appreciated. Thanks.

TB

 

[Seaman]

You need to find the root of the problem, how long are the lights left on for the tank?? Longer then 8ish hours on a non planted tank can be asking for trouble. Also a quick way to remedy the problem, would be leave the lights off and completely cover the tank for 3 days, and dont feed the fish. Then after the 3 days are up you will have A LOT less algae if any at all. BUT it will come back ifyou dont address the problem...IE: too much nutrients, too much light. The UV light will help with the green water...because it will keep the algae that's suspended in te water from reproducing, but the stuff thats imobile in the tank wont be affected.

So in my opinion Do a heavy water change and then do the three day lights out.

 

[daveedka]

Agreed with seaman for the most part.
A blackout is a good way to kill algea, I reccomend 4-5 days, 3 never seems to be enough for anything but cyanobacteria (blue green algea) the cause will need to be found, and dealt with. increased water changes, decreased feedings less light should all help. A UV will kill green water, but costs considerably more than a blackout, requires maintenance, and won't do anything for the other algea.
Algeacides are something I avoid IMO.
dave

 

[twb716]

Thanks very much. The great blackout of 2004 starts tonight!

TB

 

[Blinky]

I agree with others that the best thing to do is find the root of the problem.
Goldfish are very messy, and this could be part of the problem - 4 fancy goldfish in a 29g is actually a lot, goldfish need quite a bit of space. Algae thrive on high levels of Phosphates and Nitrates, and even with frequent water changes the levels in your girlfriend's tank could be building to a point where algae populations can explode.
If you have test kits you might want to test the PO4 and NO3 levels to see if they're high. If they are, more frequent and/or larger water changes may really help get rid of the algae by lowering the nutrient levels.
In the meantime, a blackout is a good idea. UV sterilizers are expensive; it's much more cost-effective to feed less, do more water changes and/or a blackout and go for the sterilizer as a last resort, IMHO.

 

[shanemetler]

Snails

Get some snails !!!

I have two varieties of small snails in my tank. Both are about the size of an M&M candy when full grown. I have hundreds of them in my 75 gal tank.

They are really cheap (or free) to get, and will keep your tank, gravel, plants, etc. free of algae. They also quickly devour any dead fish or decaying plant matter. They reproduce like rabbits on Viagra, so don't buy a lot. If you buy 5 or 10, they will reproduce and eventually limit themselves on the food supply available to them.

The two snails I have (don't know the specific names) are two different shapes. One is spiral in the form of a disk. Like a nautilus shell. The other is spiral, but instead of being in a round disk shape, it spirals out to a sharp point.

The round ones actually clean the glass, plants, & even float upside down and skim protein from the water surface.

The pointed ones burrow in the gravel and eat stuff deep in the gravel.

Besides their obvious cleaning abilities, I think they give the tank a natural look and their empty shells begin to make up a neat looking gravel. Eventually the shells will disappear.

I have had a tons of snails in my tank for years, and never have to clean the tank. I do occasional partial water changes, but that's it!

Shane

 

[shanemetler]

More 'self sufficient' tank advice ...

Live plants. Live plants. Live plants.

In addition to snails, ghost shrimp (sold as live feeder shrimp) do a great job eating excess food in a tank. I like feeding the fish, and always end up giving them more than they need. The snails will eat excess food eventually, but the shrimp seems to do a great job picking through left over food and consuming it before it spoils and fouls up the water.

You don't need to add extra food to feed the snails or shrimp, they will make due on their own eating left overs, waste, and algae ... whatever is available ...

Shane