Correcting CPR overflow mistake?

[clamster]

In an effort to remove CPR "Causes Problems Repeatedly" 's design mistakes:
1. Requires powerheads/redundant powerheads if 1 fail
2. Requires check valve
3. Do not want to flood my carpet for the 3rd time.

I am proposing a simple mod to the mistake I made by buying a CPR 3+ years ago.

[clamster]

This is a straight-on elevation (side view) of the modification:
black: original CPR overflow box
Red: My modifications to it
Blue: DIY 1'' U-tubes made of a combination of transparent and regular PVC and joints @ 45 degrees joints.

Basically: Create a riser tube inside the drain well to make sure there's always water in the outside reservoir to keep the Siphon in my U tube.

The CPR's internal flood well (submerged chamber) is too narrow, SO I will graft/drill/plastic-screw-on a large specimen container that will have "teeth" dremeled into it.
PLEASE CRITICIZE & ADVISE

[wave_happy]

clamster,

Generally the problem experienced by most people using the CPR overflow is that after a period of time, the overflow tends to trap small air bubbles. The small air bubbles accumulate to a point where the flow of water from the tank is reduced past the point of "acceptability" (Tank over flows). Part of the design of the CPR is that it uses the venturi portion of a powerhead to remove the trapped air. If the powerhead is submerged too deeply or becomes clogged, it can no longer effectively remove the trapped air.

If this is the problem you are trying to resolve, I am not sure what effect the additional siphon will have. Can you give more information as to what you are trying to achieve?

[clamster]

Oops, objectives went out the window:
I'm basically doing a DIY conventional U-shaped siphon overflow based on the Lifereef (is it ReefLife/LifeReef)'s U-siphon tube.

The cost of acrylic is too much and I wanted to use the existing CPR box as the basis (re-use as much acrylic as I can from the existing CPR hang-on box).

I intend to effectively DISABLE the wide "overflow siphon" that has been integrated into the CPR's design for reasons above. Right now, I have 2 ph's hooked up because mechanical devices can and DID fail. Another problem with the wide CPR siphon is that overtime, the contact points to connect an air hose from its wide siphon to a powerhead did come lose and I put in globs and globs of silicone to prevent air from getting into the air tube.

I had great difficulty cleaning the inside of the CPR siphon as well.

wave_happy,
Thank you for replying & appreciate any words (favorable or unfavorable) have to say.

On an unrelated note, I hit your homepage. Intrigued. Sounds like fun to make/have one of those things.

[aquafab]

Bad idea.

I manufacture hang-on overflow boxes.

If you use such a long U-tube to bridge the top of your design the air will build up in time because of the distance it must traverse. You will have the exact same problem... an air lock.

[aquafab]

On a conventional U-tube overflow the hang-on box measures 10" to 12" in height. The weir/dam height differential is 4" to 5" (the distance between the tank's lip to the wet divider partition inside the box). Flow rates are guaranteed to be 600 - 700 gallons per hour using a single U-tube and the proper sized return pump.

[aquafab]

Sorry my edit time limit ran out...

If you use a riser tube on the drain to make it a submerged chamber. You need to measure this height differential. The distance from the top of your new riser tube to the tank's rim to see if you are smaller than what you got now. If it is... the flow rate will be less than what is specified by the manufacturer.

[aquafab]

I took a look at the manufacturer's website at a drawing of your overflow.

Yikes.

That screen/sponge assembly on the drain is a disaster waiting to happen.

[clamster]

Thanks guys, I'll either:
1: buy a LifeReef double capacity siphon overflow
2: shell out the money for acrylic & DUPLICATE the design for the U-siphon overflow on my 26g

The price of acrylic sheets is so high :eek1:

aquafab
U said U mfg hangon overflows. Can I commission U for an overflow capable of at least 1200-1600gph? [Competative with LifeReef's double overflow box]?

BTW, the attached drawing is not to scale, and it is my half-*$$ attempt of using Windows Paintbrush to throw together some line drawings using a mouse in 2 minutes flat.

[clamster]

That screen/sponge assembly on the drain is a disaster waiting to happen

Are you kidding? My brother and I averted the THIRD!!! flooding when we noticed water level rising up to the center brace of the 200gal tank. Turns out that screen mesh trapped some lettuce/nori that came loose from the clip.

Needless to say, my CPR ran since without the mesh!

CPR = Creative Plastic Research... Creatively finding ways to flood the world's living room, one customer at a time.

[therealw00]

I have a CPR overflow...if you clean the venturi protein skimmer regularly and make sure the airline tubing isn't clogged it woks just fine and there is no need for all the mods. That said, my next tank is going to be acrylic and drilled for and overflow.:D

[ReefVan]

I also have a CPR overflow,

Got a small flood twice, then put a MaxiJet 1200 with black tubing to prevent algae growth, no more problem.

This overflow needs to be cleaned periodically and a good strong powerhead is required.

Cheapie powerhead with clear tubing = CPR flood alert

By the way, my next tank has a drilled overflow!

[aquafab]

Originally posted by clamster

aquafab
U said U mfg hangon overflows. Can I commission U for an overflow capable of at least 1200-1600gph? [Competative with LifeReef's double overflow box]?


Well thanks for the offer but I'm strictly wholesale. Besides, some of my retailer friends read me here... lol.

Your flow rate exceeds a dual overflow if you are leaning towards 1600 gallons per hour.

If it's around 1200-1400 gallons per hour I would suggest using two singles. It's always a good idea to locate the drains on opposite ends of the aquarium.

If you bought a Lifereef, I think Jeff would sell you two singles for the price of a dual.

IMO, the dual is just too darn big...

Anyways, thanks for your kind offer.