Boston Aquarium Society Message Board

A few years ago I had a green water algae problem so bad that my tank actually looked like it was glowing when the lights were on. It was a reef tank and I invested in a UV Sterilizer, which solved the problem in less than two days.

Now my friend, who just setup a small (75 gal.) fresh water tank, is having the same problem with his tank! He doesn't want to invest in a UV Sterilizer (and we live too far apart for me to lend him mine).

Does anyone have ideas on how to cure this problem without a UV Sterilizer?

Thanks in advance!

Green water can be a tough thing to fix. The easiest fix is to put daphnia into the tank. They'll eat the green water, and the fish will eat them. Another fix is to do a total lights-out on the tank, coupled with water changes to reduce excess nutrients.

UV sterilizers have really come down in price lately. You can get a 9W, which is big enough for his tank, for about $70 at Dr. F&S.

try a week long black out, do a search to see steps.

I've had good luck using Acurel F and water changes -- the Acurel F is a flocuant that causes the algae to clump up and sink to the bottom (or into the filter). This will (temporarily) clear the water.

Once the water clears (maybe an hour later) , I do a water change, as large as it takes to thoroughly vacuum the gravel (probably 50% or less depending on the tank) -- you want to move all the algae that settled out of the tank.

I'll usually do this every day or two for about a week (combined with keeping the lights off).

_________________
Rich
-- ---------------------------------------
Its new, its improved (its still a work-in-progress)
its http://redpaulhus.com !

green water is caused by a couple of things.too many nutrients from
overfeeding,over crowding,not enough water changes(including vacuming
the gravel).also too much light(either from a direct source or indirect ie
sunlight).also tanks that have not been fully cycled seem to be
prone to have green water problems.
i have had this problem in a few tanks over the years.
to fix the problem i will make extra water changes,cut back on the lights
to maybe a few hours a day.i may also cut feedings back.adding a
large amount of water sprite,frogbit or another plant that absorbs nutrients
helps.
the most important thing to do is have patience.the water will eventualy
clear.

tom

Do you have more information about her tank? Type of filtration? Fish load? feeding schedule? any plants? what kind of lighting on the tank? Is there a widow close by?

A lot of good suggestions above, but not really knowing the tank's situation makes it harder to suggest where they should start Some people might just get fed up and unload the tank when given so many possible options to solve their pea-green water situation.

ducker,


right you are...........
if they have 8 watts of light per gallon,that might be a place to start looking into.





tom