Do ultraviolet filters affect beneficial bacteria?
I have got "all ponds solutions8000" filter , running nonstop since one month , as recommended on packaging, to promote growth of beneficial bacteria. Pond is 7000 liters with waterfalls and plants . I was told the uv light kills anything that passses thru , to use it onlu few hrs a day . What is correct ?
Thank you
I'm going to be blunt and say that this filter isn't a particularly good one. It is very small and the estimated gallons it accommodates is overestimated.
That said, this filter is supposed to accommodate up a flow of 9000l/hour. We don't know how many liters you are flowing past it. Not the max the pump can do, but the calculated output of your pump given your filtration layout.
The mfg pdf for the filter indicates it can do a fishless pond of 8000l, a lightly stocked 5000l or a heavily stocked 4000l.
On to the UV question, UV's can kill anything that passes through them but it's based on the flow rate. The slower the flow rate, the more it kills. That is why most UV filters have a minimum and maximum flow rate recommendation. It's best to stay within that range.
If, however, you are looking to make it sterilize everything, then typically 2/3 of the low end minimum rate puts it into the sterilization zone.
UV's are pretty simple, if you aren't flowing enough water past them often enough, they won't work well to keep the pond clear of algae. This usually happens because people have them on one circuit of a two circuit pond.
You have to be exposing enough water to the UV to be ahead of the algae is produced in the pond.
Still learning as I go but y'all can call me Marilyn