Thread: Skimmer and bottom drain balance

I have a skimmer and bottom drain on the same line, gravity fed. The skimmer line Tees in to the bottom drain line just before the filter. Each line is 4” with a ball valve to control flow on each. The bottom drain wins out over the skimmer so to get the skimmer to pull enough for it to function I have to turn the bottom drain about 2/3rd the way off. The skimmer then pulls quite well but the water level in my Kockney koi 10000v then falls by about an inch. Why should this be, I thought the water in the filter should always be at the level of the pond?


Thanks

[QUOTE=Alburglar;425567]The skimmer and the bottom drain, should, ideally both be on there own runs, all the way to the first stage of the filter, or you will always have the compromise you are experiencing.[/QUOTE

I have two 4" bottom drains going to my drum and the 3" skimmer. I have to throttle the BD's to get the skimmer to pull -even though I am pumping 30k litres an hour total through the bakki and the bio combined. So the BD with the shortest pipe run will provided most of the supply so that is throttled the most, the second BD furthest from the filter slightly less and the skimmer not at all.