CPR overflow?

[mulron]

Not sure if you figured out what size hole you need yet but I found this on another site. Might help ya. http://reefcentral.com/calc/drain.php

[Barney]

I would drill for a 3/4 inch pvc. Anything less is likely to cause blockage in the future.

I would not let the return flow pipes go to far into the water. If so, drill a small hole just below the water line level to cause air siphoning break. This will stop water from backflowing when the power goes out.

With the split you have designed. I would try a hagen 802 and see how it goes. I just hope it is not too much flow, but with the split and turns the water has to make, I'm sure the flow rate decrease.

Hey, you're tempting me into a mini reef.

[loganj]

I agree with Barney on the 3/4" drain and drilling the siphon break. Make sure you get it under the water line though. If you drill it too high as I did, you'll get a lot of salt creep in that area. I'd have to try a Maxi Jet PH for a return pump. I get great flow from a 1200 @ 3' of head. The neat thing about the Maxi Jets is you can use 1/2" CPVC and not use any vinyl tubing. If you take a knife and slightly bevel the inside of the 1/2" CPVC, it will just slide on the Maxi Jet. It's a tight fit and will not come off. JMHO.
Logan J

[d9hp]

well, I am using the 1200 made by maxi jet

I did research ALL day yesterday and found that I will lose about 4 feet of head pressure. The maxijet shoots out about 135 gph at this height. This is great for my little tank.

When you say drill an air sihpon, do you mean...like drill a hole in the pipe, out of the water so if the pump goes out it wont fill the sump up to high and just suck water out? I kind of need a picture

I have also been told to use nylon tubing until I get to the tee, where I will then use CPVC

[Barney]

see your diagram with my red lines. Just drill like 1/8 of inch hole that will be below the water line when it is operation. but when the power go out, water will drop to the hole causing a air siphoning. i am hoping i can get the picture attached.

[Barney]

oh i forgot, make sure it is angled downward. so if the water level drops, it will be spraying a small amount downward.

[loganj]

I don't know about the tubing...I have used CPVC or PVC on all my tanks and all the tanks I have set up for others...all the way from the pump to the outlet. I haven't had any trouble with it. I suppose it would be a matter of personal preference though. Barneys advice on the siphon break is right on the money. You'll need that for sure.
Logan J

[d9hp]

Thanks a ton man! I think I will stick with the nylon until I get to the tee. I have decided on 3/4 inch tubing for the overflow

[makana]

Originally Posted by Yokhannan

d9hp, CPR's smallest overflow does 300 GPH of flow-rate.... That means it would be turning over your tiny little 7 gallon tank 48.9 times an hour 8O Perhaps a DYI project would be better

actually the cpr siphon's GPH values are maximum values, tehy can siphon any number of GPH less than the max.
ie: i use the small one on a nano with a smaller return pump so the actual turnover is about 150 gph not 300...
also wanted to say i have been using the cpr siphon for months with no problems so far...**fingers crossed**
good luck!

[Brad]

I've been running my CPR for a year now without problems. The controversial powerhead remains connected, but only operates in synch with the FW evaporation system pump. (This pump now starts up every 5 minutes or so...my idea of making more random flow in the tank)

I think it has been clarified already...but the CPR does NOT require a PH in order to restart from a power failure.

Only once in a while do I see the pump actually pull any air out of the siphon.

In case anyone thinks about this in any detail...the float switch is in the sump. Low sump level triggers the evaporation system to kick in. Any trouble with the siphon would also cause a low sump level as water left the sump and didn't return. This situation ensures that the siphon PH is turned on in response to a potential siphon problem.

[PatM]

[/quote]
If you use a standard overflow with a J tube, they are 99% reliable and do not lose prime easily. I think this is the reason that they are talked down so much.[/quote]

IMO the J tube design is no more reliable than any other, I have used commercially made ones years back and am using a DIY one now and they need to be re-primed about once a month. I'm thinking of putting one of those aqua-luft pumps on it. Any type of overflow is essentially prone to losing siphon when bubbles are trapped inside. Maybe the bulkhead the is the way to go, but who wants to drill their tank right?

[makana]

sorry for restating that...
the aqualift works great just make sure to keep salty residue from clogging up the intake tube and hole.
cpr overflows are a great, extremely reliable method for moving water IMO.