How often to backwash the filter in the summer?

[zmeu]

Now that I have this new filter I backwash once a week. Is this enough? Have only 8 koi in there ranging from 15"-28" in approx 3500g pond.

[ricshaw]

Now that I have this new filter I backwash once a week. Is this enough? Have only 8 koi in there ranging from 15"-28" in approx 3500g pond.

"Backwashing" depends on what type of filter you have.

I am guessing that you have a bead filter.

[zmeu]

It's an aqua 4000 filter. For me it also means a water change of approc 10%.

[ricshaw]

It's an aqua 4000 filter. For me it also means a water change of approc 10%.

Do you use a UV light with your filter?

[MikeM]

Once per week is probably OK with your current situation, but the real guide is whether the filter media is getting 'gunked up' more quickly. If you are relying on the bead filter for both mechanical and bio-filtration, there is something of a balancing act required. For just mechanical purposes, daily backwashing would be great, but such frequent backwashing could be too much for keeping the nitrifier bacteria robust. So, once per week is the compromise many use.

[zmeu]

Thanks for the help. My pond guy told me to backwash at least once a week. Then each time I cleaned, I noticed the pump filter needing to be cleaned and got worried. There is still the original bio filter at the top of the waterfall. I have an 80W UV system.

Fish are doing great since the major clean-up. My pond guy commented on how their color has improved, and I had noticed the same thing!

[Peppy]

For just mechanical purposes, daily backwashing would be great, but such frequent backwashing could be too much for keeping the nitrifier bacteria robust.

Mike, I'm curious about this statement as backwash frequency has also been a concern of mine for quite some time.

Someone else on the forum (sorry, don't remember who) suggested that it shouldn't matter how frequently I backwash my pressure filter because if movement doesn't bother the bacteria in a moving bed of K1, it shouldn't bother the bacteria during a pressure filter backwash.

Someone else (again, don't remember who) said the fish poo in a pressure filter is still in the water column until backwash and that's bad.

So based on these two pieces of information, I was backwashing my bottom drain pressure filter twice a day.

Could you elaborate on this for us? Like what mibht be considered too frequent backwashing?

I've cut down to once a day and I'm still backwashing before the needle on the pressure guage has moved at all.

[MCA]

I'm still backwashing before the needle on the pressure guage has moved at all.

good idea. replacing the water after each daily backwash also gets closer to an idea flow through pond.

[ricshaw]

Thanks for the help. My pond guy told me to backwash at least once a week. Then each time I cleaned, I noticed the pump filter needing to be cleaned and got worried. There is still the original bio filter at the top of the waterfall. I have an 80W UV system.

Fish are doing great since the major clean-up. My pond guy commented on how their color has improved, and I had noticed the same thing!

Note: I do not own a Aqua Ultraviolet Ultima II filter.

The Ultima II Filter Instruction Manual says on page 4;
"How often do I have to Backwash?"
"It is recommended to backwash your filter once a week, however, depending on your fish load and feed rate it may be
necessary to backwash more often, or less often. After a few weeks you will begin to notice how often it is necessary for
your own pond."

The owner's manual also suggests using a UV unit when green water is a problem.

My only comment is there are other Koi pond filtration systems that do not require a UV unit to prevent green water.

[MikeM]

Mike, I'm curious about this statement as backwash frequency has also been a concern of mine for quite some time.

Someone else on the forum (sorry, don't remember who) suggested that it shouldn't matter how frequently I backwash my pressure filter because if movement doesn't bother the bacteria in a moving bed of K1, it shouldn't bother the bacteria during a pressure filter backwash.

Someone else (again, don't remember who) said the fish poo in a pressure filter is still in the water column until backwash and that's bad.

So based on these two pieces of information, I was backwashing my bottom drain pressure filter twice a day.

Could you elaborate on this for us? Like what mibht be considered too frequent backwashing?

I've cut down to once a day and I'm still backwashing before the needle on the pressure guage has moved at all.

I checked out the info on the Ultima II line and see that it uses a K-1 type media. If the pressure filter uses a K-1 type media, backwashing will not have the same impact as with one using beads. The greater agitation involved in pressure filter backwashing compared with a moving bed application might be rougher on the biofilm, but probably not to a material degree. So, my comment does not apply to your situation. The real test, of course, is water quality. If there is no detectable ammonia or nitrite, and nitrate levels are low, and these results are consistently obtained, you're doing it right.