garden fish pond filter question

[BJS]

I have had a fish pond for about 9 years with a assortment of pumps and filters. I found that normally the sponges in the filters had to be cleaned almost weekly. However the present sponges were fitted into the filter about 7 weeks ago and the output flow is still good. How often are other fish pond owners changing their sponges.
Thanks in advance for any replies as I find it strange after being used to having to clean sponges far more frequently for all these years.

[landscaper2]

Lucky you! Not much of an expert re fishy matters, but here's a few possibilities - maybe the pond has reached a balance naturally and of course this has been a relatively cool summer with less sunlight, which will slow algae growth. Could be you have a more coarse sponge or if your sponge filter is in the pond, have you raised the inlet a little, above the sludge? I hope you have filled all that spare time productively!!

[RATTER15]

I have recently purchased a small 12v (via mains transformer) pump from B&Q, surprisingly good and there is no filter on it and it works perfectly, it has been running constantly now for about 5 months without missing a beat!!

[Dragonmist]

I had a huge, ugly, very expensive filter with UV lamp. It has 4 large sponge blocks which were suspended below a plate..Theoretically the water had to pass up through these sponges over the top of the plate and out. It didn't work, and if the sponges were blocked, which always happened when I was out, it either shut off the pump through back pressure and backflushed all the nasties back into the pond, or it overflowed, half emptying the pond. The "biological" part never worked.
After a year I gave up with it. I bought an Ecocell which came minus UV, and only 1 filter sponge over the biological media. I got a pack of 3 sponges of different density, and 3 weeks later the pond was much cleaner. I had to clean the sponges every few days at first while it got to grips with the pea soup. Now I can see almost to the bottom, and the water is coming out of the filter almost clear, if still tinged fainly green. Once a month I rinse the sponges in a bucket of pond water. If they are too bad they get shoved through the washing machine on a cold rinse programme. Works like a charm. There are enough biological entities left in the filter base so it doesn't seem to matter.