pvc overflows?

[bobberwobber]

hi again. i got the filter built and worked great, however, the pump i had is a little too big for my HOB overflow. the sump is in basement, so pump needed to manage about 7 foot head, which this does, a bit too well. (quietone 2200) anyway, irrelevent because i managed to break my HOB overflow after i tried to fix a leak in the drain pipe.. oops. confidently priced a new one, $100???? buy a tank for that.. anyway.. i been looking at a few of these DIY pvc pipe overflows. which be ideal, as i can scale that up to handle the pump and personally, think be easier to hide a single pipe or maybe 2, than a large acrylic, algae covered box. question is, anyone else used these or built one? i searched but got no results on here. i know ideal is drilling tank, however, it being built in to a wall is a problem and my local store cant do it, so id have to transport it an hour north, in the back of my truck, which scares me. plus i worry about leaks developing and already had one flood, i may not survive a second! (im still hearing about it)
just wondered if anyone had some positive, or negative experiences with them?

 

[partypalooza5]

I've built a PVC overflow before and honestly I say while the principal works fine, it's not super good for the long term. The siphon is easy to break in comparison to a "U" tube (probably because the open end of the pipe is exposed to the surface? Not totally sure...)

I'd say look into an Eshopps overflow, I have one and can honestly say it works great. Hasn't broken siphon once! (My apologies if you already had an Eshopps. XD)

 

[th08tu]

I also tried one for my nano, however I could never acheive the amount of flow I needed, even for a very small return pump. It worked and the siphon stayed with the pump off, however I didn't get much water coming out of it...

 

[bobberwobber]

dont know what brand mine is/was. came with the wet/dry filter which was given to me few years back and sat in the basement. just standard looking one. single U-tube and 1 inch stack pipe with 4 holes in it. no where near enough gph for new set up.
thats what i am wondering with the pvc.. getting the right gph. all seem to use 3/4" pipe. i dont see why cant upscale to 1" or even 2 of them, joining to a 1 1/2 pipe down to basement. i have an advantage of the wall covering 7inches or so each end of the tank, so can hide stuff behind there, but i dont know how id calculate the flow rate.. other than trial and error... seen claims of 600gph etc.. but i find that hard to believe... any engineers out there who have some magic formula for that?

 

[saltwatertogo]

about 900gph for a 1" overflow hole is a good rule of thumb, the problem with a pvc overflow is you can't see if it develops bubble, and this usually happends when there is not enough flow going through the pipe and it allows air bubbles to form in the tube thus stopping flow, and tank overflows. u-tubes you can at least see the bubbles forming. be careful abuot drilling most places won't gaurintee it won't break, and be sure it not tempered glass they can't drilled good luck

fishman

 

[bobberwobber]

thanks... 900gph be more than enough. i got the stuff to give it a go tonight. figure if it doesnt work, im out $10.
yeah im not drilling.. did just pick up another long 55gal for $20 from craigslist.. i may see about getting that drilled. or just set it up as a refugium downstairs.. dunno.. thanks for the input