Question
I have a small pond (400 gallons) with a pump running 24/7. There is no leaf/debris problem but it seems when it rains the water turns a medium dark tea color (the water always seems to have a light tea color anyway (it is a new pond only 2 weeks old). I dont have a filtration system (just the foam spounge thing that goes over the pump intake part which I remove and rinse off twice a week or so). I read up on the web and it seems it is tannin but the cure is stated to use carbon put in mesh bag put in the filter but I don't have a filter. What can I do to clear up the tea color. I am also trying to make sure there is no runoff into the pond when it rains. Can that make the pond water turn a tea color that never seems to go away? I have a fountain in my front yard and the water in it seems to turn a tea color too when it rains, can it just be the rain, maybe filtering through the trees before it hits the water? I am just making a lot of guesses.

Thanks for your help!

Answer
Brown water can be due to tannins and lignins from leaves and branches or from dirt.  If it's dirt, it is usually cloudy brown as opposed to a clear brown.  Do you have mulch near the pond?  If so, it could be releasing lignins and tannins into the pond.  As the mulch ages, it wouldn't release as much brown into the pond after rains.

A filtration system is a good idea for your pond regardless.  You can put a mesh bag full of rinsed off activated carbon in the filter or in moving water.  That will remove many of the lignins and tannins.  You don't have to have a filter.  You do have a pump so as long as some water moves through the bag of carbon, that should do something.  You can have the bag of carbon right in the pond too.

If the brown is due to dirt washing in, a filter would help.  It should also settle naturally over time.

Water changes will also help in either case to dilute the brown color.

It's not likely that rain would be brown or pick up something brown from the trees.  I suspect that in your front fountain, if it's just water and nothing else, the brown might be some brown algae growing.  Brown algae (both suspended and attached) likes shade and is not all that common outside.  I assume that your tap water is clear?  Could anything be washing into the front fountain?  Those are my guesses!

Good luck!
Robyn
fishpondinfo.com