Sump level staying below minimum level

berryblonde2u · Jun 29, 2014

I have a Oceanic 90g bow-front tank. It has a Durso set-up. I have a 1 1/2" drain and a 3/4" return. I have a 2 baffle sump consisting of a wet/dry filteration system and a holding chamber (not sure if that's the right teminology) I have a coral life skimmer mounting externally on my sump which btw is working like a champ). I am using a Danner Mag-Drive Supreme 9.5 950 GPH Water Pump for the return. I'm having two issues. #1 it sounds like a washer draining (worse actually)Sounds like I AM INSIDE a dishwasher. I already had a vent hole on the top of elbow in overflow (internal). I drilled it to make it larger, but that hasn't worked.When the water drains into the 1 1/2" hose you can actally see a 1/4"-1/2" inch gap of air to each side of the flow coming down the hose! There is no siphon obviously because it goes in my w/d filtration sump. The 2nd issue is that my sump level is running below minimum level. It's still covering both pumps (protein skim. and return). I originally had floss in there for polishing, the water looked incredible, problem is I had read that some sponges and floss can slow water to return pump. So I removed it (water quality reflects the change!) I have tried adding water to both the DT and the sump without effect. My water in my DT is right up to the black trim! As soon as I add water to sump it goes into DT. I bought the stuff for a ball valve on return line, but I keep reading that pump will try working harder and may burn out? I have read about gate vale either on return or drainage, but there seems to be debate with this to? I welcome any feedback that any of you may have. I would really like to add my anxious fish and stock to their upgraded home!

Sorry this was so long, but I tried to give you the info you all would ask. LOL:

3Twinklets · Jun 29, 2014

Have you checked for salt blockage in your vent hole?
Have you cleaned your main drive pump?

berryblonde2u · Jun 29, 2014

Yes, Wendy. I checked my vent it is completely free of debris, I even drilled into it making a larger hole. I have cleaned my main drive pump. It could use a new impeller, as it is getting worn. I wanted to make sure I don't need a smaller pump before I pay more $ money for a new impeller. I believe the magnet is showing some evidence of wear. What else you got ?? LOL

3Twinklets · Jun 30, 2014

OK heres what I've got Lol!I have a gate valve on the line that goes from the pump into the tank. This helps to adjust the flow.Is your tank maintaining the level that you want.Can you show a photo of your overflow? I wish I could see your setup. Is there a vent hole cut into the elbow at the top of your overflow? If so, try cutting a piece of tubing hose about 6 or 8 inches long. stick it down into the hole and let the reat hang over the side of your tank.

AZDesertRat · Jul 1, 2014

Photos really help.
I am not a fan of drilled holes, they plug and fail. As long as you keep the returns submerged just under the surface you will only backsiphon enough to expose them to atmosphere before they are exposed to atmosphere and the siphon breaks, this is called an air gap and is the simplest, best form of backflow prevention known to man. Requires no maintenance and does not make any noise either.

You might also investigate the Ken Stockman standpipe design on Durso's website, I find it to be much quieter and almost impossible to plug with its shrouded design. I drill the hole in the top cap just large enough for a piece of vinyl airline tubing to be inserted snugly then slowly work the tubing up and down a fraction of an inch at a time until the overflow is totally silent.