Dirty water

[Graham Katz]

Hi my pond is 25000 liters with a koi sand filter, bio filter and a uv filter it has a weir basket much like a swimming pool construction. My plant coverage with water lilies and water cabbage is about 50%
My pond is green and I can hardly see my koi fish can anyone advise what I'm doing wrong.
I backwash the sand and bio filter at least 3 times a week as I don't have a bottom drain I use my pool vacuum cleaner with the pump set on "waste" to suck up the fish waste once a week, pond still green

 

[Tula]

Welcome Graham How old is your pond and how many koi do you have ?

 

[cas]

Hi Graham. Have you tested your water? Do you know what your ammonia reading is? Green water is not necessarily a bad thing. Suspended algae (green water) feed on ammonia so when ammonia is eliminated, the green water will be eliminated. Algae blooms are also caused by excess nutrients (fish waste), not enough plants, too much sunlight or low oxygen levels. Other plants that are helpful in controlling nutrients are anacharis or hornwort. As Tula asked, how old is your pond? Until the pond gets established we all have had problems with green water. I added an aerator and it seemed to help with the green water.

 

[sissy]

Maybe you need more oxygen in your water .The more I added to my pond over the years in air really does help .Moving water helps also .

 

[Ruben Miranda]

Hello
Where are you located and do you know the temp of your water?
Is this a recent advent or has it been green for a while?
I read you are back flowing the filters to clean them.
Are you doing any water changes ?
I am kinda guessing here but I think that your Pond water temp is low (do to winter) and your plants have slowed down in growth and using nutrients, and your nitrates and phosphates are high and causeing a Algea bloom.
I would do a suggested test for
Ammonia and nitrites and include nitrates and phosphates

Ruben

 

[Graham Katz]

Welcome Graham How old is your pond and how many koi do you have ?

5 months old

 

[Graham Katz]

Hello
Where are you located and do you know the temp of your water?
Is this a recent advent or has it been green for a while?
I read you are back flowing the filters to clean them.
Are you doing any water changes ?
I am kinda guessing here but I think that your Pond water temp is low (do to winter) and your plants have slowed down in growth and using nutrients, and your nitrates and phosphates are high and causeing a Algea bloom.
I would do a suggested test for
Ammonia and nitrites and include nitrates and phosphates

Ruben

Hi I'm in Harare Zimbabwe so water very warm yes I add fresh water twice a week
I also think my water flow rate is too quick for the uv filter

 

[sissy]

Could be the lower the water flow into a uv the better it will work .Faster is not always best

 

[Tula]

I had to slow the flow by my UV, as it was too fast....it made a big difference.