Can Bio balls become toxic

[Fish Hunter]

Hello All:

New to this form.

I have a 300-350 gallon preformed pond with a Tetrapond UV bio filter 1500 with a Pond Master 2000 prefilter and Lifeguard All in one filter. My water would run high on nitrates all the time and I had to do frequent water changes. Also had hair algae growing in my stream.

About a month after changing 1/2 of the water and pre-filter/bio rinse, the nitrate would run high again and the koi’s were sluggish and would not eat and stay at the bottom of the pond and if I didn’t catch this, I would lose a few of them.

Frustrated I changed the bio balls inside my Tetra Bio filter with a new set. Low and behold, the water nitrates is now good and the hair algae that grew in my stream and on the edge of my waterfall that feeds to my pond went away.

Never heard or knew of bio balls becoming toxic or contaminated.

Anyone else experience bio balls going bad or toxic?

 

[bettasngoldfish]

Nitrates are going to be an issue in a pond that small with koi in it. The best way to keep them under control would be frequent water changes and lots of live plants.

Bio balls should not be replaced. Only rinsed in bucket of pond water when necessary.

 

[Fish Hunter]

Thank you.
The Tetra Pond Bio Filter has a reverse flow bio rinse function that I do when I rinse the pre filter.

It’s been 4 months now with no issues since I changed out the bio media. The fish are more active, No lost fish, no more hair algae in the stream that feeds to the pond.

What kind of plants do you suggest?

Thank you again for your reply.

 

[bettasngoldfish]

Anacharis and hornwort are fast growing plants that can be left floating under water. If you prefer plants floating on top of the water, water lettuce or water hyacinth are a good choice. Both will have nice roots and will multiply in the right conditions. If you have a place for potted plants some water celery, water iris, watercress are all a good choice.

You should probably go with plants that are hardy to your area. Or at least most of them. Also keep in mind how much sun or shade you have and choose accordingly.

 

[Fish Hunter]

Dear B&G,
Thank you for your reply. I will look into this.

FH