HOB Filter as a HOB Overflow???

[Miguel4u2]

Bitteraspects Your just a buzz kill...lol...its purely for curiosity.
Take no offense, I realize its not a good idea, was just curious
Thanks for your help

No way I'm going to pay for an overflow box, there to expensive for nothing, if I do an overflow im doing pvc or drilling the back of my tank...

They are not expensive, well not on ebay. You can get a 1200 gph with u-tubes and the tubing that goes to the sump for just under $50. Its less than a HOB filter

 

[rojowe]

yeah but for maybe $10 I can grab pvc and fix up my own...just saying...
the idea for the hob is because ive got 2 extra

 

[bitteraspects]

They are not expensive, well not on ebay. You can get a 1200 gph with u-tubes and the tubing that goes to the sump for just under $50. Its less than a HOB filter

or for under $5 you could build your own overflow.

1.5" PVC will give you over 1200gph (1350 give or take) and 10' of 1.5" PVC is under $3.

 

[TheCanuck]

if you used U shape tubes inside of the HOB and didnt use the pump inside of the HOB, yes it would work , just fine. But you would have to cut a hole in the bottom of HOB , then put the U tube in the tank and in the HOB, it woulnt use any electricity either... I think people are failing to understand your design.

 

[JakeH]

Again. NO
Even if you got two of the same model powerhead, the flow rating is a rounded average, not an exact measure. And even if you got two powerheads that flow exactly the same, the slightest build up of algae or debris in the intake or impeller housing will cause enough of a slow in the flowrate (however slight it may be) to make the return pump faster than the internal siphon and flood the tank.
Then there's the issue of head pressure.
Most powerheads are rated at 0 pump head, and not meant to operate under such conditions. So again, even if you had two of the same model powerhead, the head pressure of the powerhead pumping water vertically over the lip of the tank and from the "sump" back to the tank, would cause them to pump Irregularly and at completely different flow rates. Not to mention, the added stress on the impeller and motor would put added stress on the powerhead, causing it to eventually fail.
And the list goes on and on and on...


As you have been previously told, stick to the tried and true methods rather than try to reinvent the wheel.
A PVC overflow is cheap, easy to assemble, and reliable.

K.I.S.S.
Words to live by.

I understand your points about the flow rates & head pressure, but I already mentioned that there would be some pump-sizing & matching to do in order to get the balance right. Besides, most of the powerheads I've used have a pretty good amount of adjustment built in. I'm not too worried about extra wear on the motors, though. We're only talking about maybe 120 gph & 3 feet of tube. That would be nothing for a AquaClear 50 (270gph) or 70 (400gph) powerhead. Seems like it could be scaled up or down easily too, with multiple intake and/or return powerheads. I feel like it could be done with enough trial & error (and towels)...
I agree that debris/algae build-up could be an x-factor. I hadn't thought of that, but I still think you could get around that with a prefilter...

Somebody help bitteraspects convince me!

 

[bitteraspects]

Its obvious that no amount of information is going to "convince" you, so like I said, tr it cor yourself and see what happens.
Make sure you do it on a large tank in your living room.

 

[Miguel4u2]

yeah but for maybe $10 I can grab pvc and fix up my own...just saying...
the idea for the hob is because ive got 2 extra

You are not getting the point! Its better to be cautious than to be CHEAP. Your idea wont give you any decent filtration at all and if you drill your tank, there will be a chance you can ruin it and the tubing will look ugly in the tank. The overflow box is the best thing you can buy. It is the best,safest, and most successful alternative for a non-drilled tank. And if you got 2 extra HOB's, why not just use them?

 

[bitteraspects]

You are not getting the point! Its better to be cautious than to be CHEAP. Your idea wont give you any decent filtration at all and if you drill your tank, there will be a chance you can ruin it and the tubing will look ugly in the tank. The overflow box is the best thing you can buy. It is the best,safest, and most successful alternative for a non-drilled tank. And if you got 2 extra HOB's, why not just use them?

how do you figure an overflow box is any safer or more efficiant than a PVC overflow?

An overflow box is at the same risk of cavitation and shut down as any other overflow system, along with any other risks associated with using a wet/dry system. And since the mechanical function of any surface skimming overflow (be it PVC, box, or drilled) is going to be the same based on how the return/ powerheads/ etc are plumbed, that leaves flowrate v. price.
Since you can build an overflow with a higher flow rate for a mere fraction of the cost, and it will be just as effective and safe to use, seems to be a no brainer.

Then there's the option of building a "bottom siphon" style overflow. While you would need to go with a slightly larger diameter PVC to get that same 1300gph flow rating, the bottom siphon overflow offers all the same functions as the above mentioned overflow systems, but also gives you the added benefit of increased mechanical filtration.

So again, in intrigued to ask. Why is a overflow box "better" than a PVC overflow? Because its more expensive?

 

[TheCanuck]

i use pvc and overflow boxes. I personally like the pvc better , just because i made it.

 

[nfored]

I like overflow boxes, as they take up less room in the tank, I am pretty picky about what you can see in the tank. I have mine drilled and I hate that I have to have teh 90's showing where it drains out. However this idea the OP has will work just not well