I've wanted to get rid of the bubbles that get into my DT. There isn't a lot but and some say it's bad and others not so much. I've never had so many that I had an issue but it was always bothering me in the back of my mind. I noticed that if I had the ball valve going into the sump fully open it would create more bubbles than a bubble wand. I have the two lines coming into the sump. One goes into a refugium that flows out to the main sump and this is reduced to a slow amount. The other goes into the skimmer section. If I had to guess I would say 25% goes refugium with the rest going into the sump. So the sump ball valve remains somewhat closed as I mentioned fully open just creates a bubble factory. Inevitably when I'm doing PWC
's I usually end up with more water in the system than what I took out, not by much, but anytime that happens the bubbles almost disappear with the higher level in the sump.
I do have a bubble trap before the return section in the sump and I have a 12 gallon top off container with a float valve in the return section to account for evaporation. Today I raised the level of the float valve to keep the level in the sump higher and hopefully less bubbles.
So I guess in a long winded way are there better ball valves that don't cause bubbles when fully open? Are other people's tanks that sensitive to bubbles and water level changes?