PVC overflow
- Thread starter AndrewMack
- Start date
I was just thinking.... you could feed a canister with these too right? -Even combining two into one to ensure enough flow? That way if the canister has a failure, you are still protected from total flood?
A true overflow setup wouldnt necesarily work well with a sealed canister. For one thing, if water evaporated just very slightly then the water level in the tank would drop and water would no longer flow over the overflow and your filter would run dry. In a overflow with a sump, the evaporation shows by declining water level in the sump, the water remains constant in the main tank (if it didnt, it wouldnt be able to flow over the overflow). If you had a true siphon then it would be the same thing as what canisters already come with for the most part.
I quickly learned that this overflow design doesn't work with a trickle filter for a couple of reasons.
1. During a power failure the siphon is lost. For the siphon to stay intact, the T must be under water at all times.
2. The T leading to the sump stay under water to prime the unit during the initial start.
Am I missing something? Is there any mods I can make that I have overlooked?
Rohn
1. During a power failure the siphon is lost. For the siphon to stay intact, the T must be under water at all times.
2. The T leading to the sump stay under water to prime the unit during the initial start.
Am I missing something? Is there any mods I can make that I have overlooked?
Rohn
I disagree...on my wet dry the outlet from the overflow sit above a drip plate and never touches the water...I have never lost siphon....
are all your joints glued and sealed???....any leak will cause you to loose siphon
If done correctly many have had no problems loosing siphon with this setup. When the power is off the T isnt realy underwater anymore - look at rallysman's picture and you can see the red actually stops at the lower part of the T. What some do to avoid loosing siphon on HOB overflow boxes is to drill a small hole on the main over the tank piece and instal a Tom Aqualifter pump so it continously pumps water and/or air out to keep the thing primed. The water shouldnt ever rise above the middle of the T anyhow, unless it is cloged or two small to allow free flow. Once water starts flowing and it gets up to the T, as soon as it comes up to the middle part of the T than it will spill over through the middle and down to your sump.
What I could get it to work until I had the T below the water. I install check valve on top of the U (one outside the tank) to prime and start the siphon. I just could get it to start until I submerge the T under water (in sump).
I must have done something wrong. I will go back and double check my joints.
Rohn
I must have done something wrong. I will go back and double check my joints.
Rohn
I did a DIY overlow similar to the one pictured about 5 years ago on my 130 gal. Not sure where the pictures went, lost in cyberspace but after a few months I bought a CPR overflow and ran it for 4+ years before the tank sprung a leak.
I would never build one again. It was mainly noisy and It's difficult to strain the intake without backing it up and when the intake gets clogged your system fails and if you're tanks small enough you can easily overflow the tank from the water thats contained in the sump.
A HOB overflow or one drilled through the bottom of the tank are QUIETER and SAFER options. Spend the $ it's well worth the piece of mind!
My new tank has corner-flo's with the drains and return pipes coming up through the bottom of the tank. (I got the perfecto 180) .. These cornerflows take water from mid level in the tank as opposed to just the surface and I've found it works AWESOME.
Anyways, $100 will get you a good HOB overflow that will be quieter and safer.
I would never build one again. It was mainly noisy and It's difficult to strain the intake without backing it up and when the intake gets clogged your system fails and if you're tanks small enough you can easily overflow the tank from the water thats contained in the sump.
A HOB overflow or one drilled through the bottom of the tank are QUIETER and SAFER options. Spend the $ it's well worth the piece of mind!
My new tank has corner-flo's with the drains and return pipes coming up through the bottom of the tank. (I got the perfecto 180) .. These cornerflows take water from mid level in the tank as opposed to just the surface and I've found it works AWESOME.
Anyways, $100 will get you a good HOB overflow that will be quieter and safer.
