I have set up a fuge and everything seems to be going the way I was thinking it would except one. I am having trouble with the amount of water that continues to trickle into the main tank once I turn power off.
Basically the set up is this. I have a 20 gallon tank sitting beside (slightly raised above) my 24 gallon aquapod. I have a small pump in the back right chamber feeding the fuge. I have a 1" diameter return line that drains (via overflow) into the back left chamber of the display Aquapod. When I turn on the pump the back chamber drains a lot before any overflow happens, but once I stop the pump it keep trickling for a long time.
So my issue is if I put enough water in the system so that the back chambers don't lose so much water the pumps back there run dry, I get too much water in the display once the power to the feeding pump turns off. This is hard to explain but I hope it makes sense.
Any suggestion as to a way to fix this? Thanks in advance for any help!
The only thing I can think of is to put the pump outside the chambers into the visible area of the tank. I don't really want to do that though. I just don't get the science behind why there is such a delay with the overflow. BTW this is not a siphon issue. The feeding line and the return line are above water.
I had a similar issue with my old 30G tank and above DT fuge.
Essentially, the issue is that the drain on the fuge initially can't keep up with the flow rate (as a result of air and water mixing and reducing flow). This results in your chamber draining before the fuge drain catches up. You can either A: reduce the flow from your return pump or B: Modify the drain setup on the fuge.
I would opt for option B. How is the drain currently set up?
As for the trickle on the return when the pump is off, you likely have a leak on the drain pipes inside the fuge. A bit of water is seeping through. You could try gluing all of the pipes together inside the fuge (not my first choice) or use teflon tape between the fittings, or do nothing and over time, crud will likely build up and seal the pipes.
My fuge is just a 20 gallon drilled tank. The overflow return line is just a bulkhead with 1" flexible PVC running horizontally towards the main tank. So once the water reaches the bulkhead it starts to flow down the PVC tubing towards the tank. My pump is small and my PVC is fairly big. When it is running I have plenty of room for the water to flow back to the tank. I don't think there is any issue with my return line not being able to handle the amount of water the pump is sending to the fuge. When it is going everything is fine. Once it stops I just get a delayed effect of water continuing to flow into the main tank. It stops after a while but it gets very close to overflowing the main tank.
Got any pictures? Maybe that can help us picture the entire setup.
Yes need to see pics, but what I would do is put a valve on your return line, so you can control the flow better.
I was just writing that.
I run 3 large tanks basically the same setup.
I prefer slow water travel through my refuges.
More time to filter water that way.
I use a ball valve to slow down pump to
fuge. With everything turned off, check water level
as you mentioned it almost overflows the nano.
Lower water level to a comfortable level, and ball valve
adjust to sump.
I will take a picture when I get home. I have a very small maxijet down at the bottom of the first chamber. With the amount of height it has to go the flow is fairly low. I guess I could put a valve on it but then I am just wasting heat into the tank since the pump is still producing the same heat but for less flow. I would prefer to get an even smaller pump if I wanted less flow. I still think the same thing will happen with less flow. I just think the chambers will drain slower. Once they drain to a certain level the overflow will begin to flow. Once I shut it off the overflow will continue to flow until the chambers are full again.
So again the problem is if I add enough water so the chambers don't empty too much, then I get too much water in the tank once the pump is turned off. If I don't add more water to the main tank the chambers empty to the point where the pumps run dry, but when I turn off the pump the chambers fill back to normal.
Maybe you are right Bob. Maybe the only thing I can do is slow the flow down so much the lag time is reduced so the amount of water in the transition period is lessened.
Man this is so hard to articulate. Am I making any sense????
Yup lost me lol
pics pics pics lol
If your return line is almost horizontal (like mine was), it takes a while to build up enough head pressure to get the water flowing from the fuge to the DT. In addition, when the return pump is first turned on, the air and water mixing at the fuge drain will tend to block the flow somewhat until they reach equilibrium. Combined, these two issues will cause the chamber drainage issue that you are experiencing.
Throttling back the return pump will help.
Changing the fuge drain setup will help.
Increasing the height of the fuge will help.
Consider how small the chamber in you nano is
compared to the surface area of a 20 gal. tank.
Obviously, you are draining out the nano
faster than the water level can rise in the
fuge to flow back. Definitely need to throttle back
on pump to give nano a chance to keep up.
You'll never guess at it by using a smaller pump.
Make sure fuge drain is downhill all the way bac.
Test Test Test
Okay thanks for the suggestions. I think I definitely need to raise it up some more. I will get it going down hill more. In the picture the end of the PVC is resting higher than it normally does so that it doesn't flow into the tank anymore (it normally goes under the inlet rather than over it like the picture shows. That was how I stopped it when I thought my tank was going to over flow. Regardless, I do need to have a greater downhill towards the tank once I get it going again. I also will put a ball valve in to slow my pump down. Thanks Bob, you have been on me for a while now to get the flow down, I think you finally beat me into submission =). I see the value in that now. I guess I just hate wasted flow since I am so concerned about having enough overall flow in the tank. Thanks Rybren for the head pressure thought. That is exaclty the science of it I needed to understand. Now that I get it, I am okay with making changes to fix it. I just hate making changes without the reason for the problem known. I will update photos and status when I get it going. Thanks again all!
for starters.. replace the filtered drain piece to an elbow pointing up. You will create some build up in the tank using pieces like that. I have the same thing on my fuge and it does the same thing.
Thats if you can make it work.
Nanosf, you mentioned keeping your flow up.
It's more important to turn over the tank itself
around 10 times an hour which is easy
with a single powerhead in the nano.
To and from the fuge can be slower, In my
experience, it needs time in the fuge to get filtered.
I don't know why I am so interested in more flow. I just worry my PH will be dragged down if I don't have enough. My PH is always on the low side and I never know why. It is stable and I know that is the most important thing, but I don't get why it is low.
I will be getting a valve to limit the flow.
WOOO HOOO. Problem solved. You guys are geniuses! I combined all the solutions form OVAS plus some help from the Marinescape guys, and problem solved.
Thanks a million to all those who took the time to help. Bob P, Jetjumper, Rybren, Rush, you are all awesome.
So basically I used an upturned elbow (chopped off a bit because I didn't have much hight to play with). I tried to buy a valve but couldn't find one so I rigged up something to squish the line. Finally I raised the whole fuge up 2 more inches.
Now I have only 1" of drain down in my back chambers. I learned the term from the Marinescape guys. I guess if I knew that term (drain down) it would have made my explanations much easier to understand :)
So when the pump that feeds the fuge comes on the chambers empty to about 1' lower than they started, and when I turn off the pump it drains down and fills back that 1". I can handle 1".
So now I need some cheato for the fuge, plus a cabinet to cover it up and hold my lighting, and I'm all set.
Thanks again all!!!
Quote from: NanoSF on February 11, 2011, 03:18:01 PMI can handle 1".
Thats what she said!...
Glad you got it all working! :)
Cool
love it when a plan comes together