Excellent pics!! But I have a ?; is there an overflow in the top of that first section. The one inside the tank. I can't tell. Thanks TomRoy L.;301732;301732 said:
diy overflow
- Thread starter eh1421
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Ya, can someone take pics of all sides top bottom and all around so I can get a better understanding? I want to put this in my 250, I have 2 mag 12's and 1 mag 24, should I use 1 mag 12 with 2 of these pipes? I need to get the poop off the bottom, would this work if you had the intake part almost to the bottom of the tank? Thanks.
Can someone give me an idea on how I can plumb the rest of this. I have it set up like opposite of a spray bar. There are 2 pipes going down each side of the tank with albows connecting the lower pipe wich is an intake with holes drilled along the length. I need to pick up the fish poop from the bottom.
what are you trying to do? not sure if that can be much of an intake for your overflow, more like an intake for a canister unless you make the overflows kinda weird. i dont think it would flow well.
Well I want the pipe with the holes to suck up the poop while sucking in water, down to my wet/dry. I can make the holes huge. I know it looks weird but I can hide everything easier this way and it will suck up all the crap on the bottom, I just cant figure out how to plumb it beyond what is in the picture.
built this recently and works great. one thing i noticed is that it seems like my siphon is fluctuating. i notice the water level in my sump rise or lower about a half inch or so over the course of a few hours. is this common or am i still getting air trapped somehow?
I call this bounce and if you look the water in your tank also rises and lowers. It seems to me after building a few of these what happens is you get a air vortex that sucks down from the intake inside the tank this air flushes with the water through the pvc into the sump. As this air flushes some of it becomes trapped at the top loop(where check valve is installed) this slows the siphon. As siphon slows the water in the tank begins to rise as it rises the water pressure above the intake builds until there is enough pressure to flush the air from the line. When this happens the siphon returns full force and the tank water drops. Then the cycle repeats itself. I've tried many things to figure a way to prevent this but as of yet I havent been able to figure it out. Hopefully I will soon. Hope this helped explain whats happening with yours.islander671;553669; said:
Jawbone;554392; said:
Thanks man i think that is exactly whats going on with mine. do you think lowering the intake tube away from the water surface would help prevent the vortex from occuring? or would that just make a bigger vortex?
I have tried this, if you go low enough its seems to help but the problem then becomes if there is a power failure all that water above the intake will siphon to your sump. I guess if you had a large sump it may work. Then I found out doing this created a new problem if power goes out water siphons down to intake, when power comes back on siphon begins but the air vortex starts at low level and keeps water from rising up high in tank. Hope that made sense. Another words water level would not return to the level before the power failure excess water will just stay in the sump. Some solutions I'm working on are, its been suggested one cause for this is having a siphon overflow that is cabale of taking much more water then pump can provide. So the fix would be install gate valve on pump return(meaning after pump) and gate down the flow till the overflow and return levels out. I havent tried this yet but in theory it seems this may work and prevent the bouncing. Also I found that if you introduce a piece of air line tubing to the intake and control the flow of air going down the intake it helps regulate the bounce. I've down this but it takes some fiddling with up and down in the intake to get it adjusted just right. I'am working on this problem now so when I find a solid solution I will post it here. Hope this helps.islander671;554490; said:
One other suggestion I forgot to mention is adding another overflow same size as first one to the system. What this does is allow overflows to regulate more evening controlling the air flow into the overflow thus eliminating the bounce effect. This would work similar to throttling your pump back with gate valve. Another suggestion is placing valve on back of tee on overflow to dial back overflow. I havent tried this but I dont like the theory of restricting the overflow. In this idea if the bounce were to occur you would need higher water level above the intake to flush the overflow which if high enough could overflow the tank. Another thing suggested was having tube come over top of tank and go down into tank then leave of the elbows and riser pipe of intake. The tee outside of tank would have to be signifactely raised to prevent siphon the tank all the way down in power failure. I've done this it seems to work but this design greatly reduces the flowing capability of the overflow. Flows way less.
