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adidas
11-13-2006, 02:35 AM
I've got a cpr overflow, and last night the tank overflowed (the powerhead that keeps the syphon going must have crapped out) got it going again but i'm very paranoid about it. I had an idea for a flood fail-safe, I thought i'd run by you guys...

has anyone ever tried putting almost like a gutter around the outside of the tank? like using silicon to stick 1" pvc, cut in half, around the outer edge with a slope and a couple pipes draining to the sump? My tank is in wall and i could have it out of view.

thoughts?

beaker020
11-13-2006, 07:00 PM
Well, you could put the gutter around 3 sides but not the front and unless you tilted the tank slightly to the rear to ensure that the tank overflowed into your gutter and not your living room It would still be a problem. Tilting the tank, however, is never a good idea and creates its own set of problems, not the least of which is catastrophic tank failure.

Your options, as I see it, are:


have your tank drilled
get a better overflow like a Lifereef. Even the best external overflow can fail however.
install a safety cut off switch: A float switch and circuit that cuts off your main pump when the tank gets too high or your sump gets too low.

Joe Reefer
11-13-2006, 07:48 PM
I have used a CPR overflow for over 2 years now, it has worked great. It does require some maintainence ie. replacing the siphon hose and cleaning the pump. IMO these devices get a bad rep. our systems require attention almost everyday, to me it is nothing to check and see if the overflow is functioning properly while feeding or dosing.

bassman
11-13-2006, 07:54 PM
What I did was put a float switch in my sump. If the water gets too low the switch turns off my pump. Hence, if the water does not return from the display tank the water level in the sump will drop and the pump will shut off.

adidas
11-14-2006, 01:46 AM
Well, you could put the gutter around 3 sides but not the front and unless you tilted the tank slightly to the rear to ensure that the tank overflowed into your gutter and not your living room It would still be a problem. Tilting the tank, however, is never a good idea and creates its own set of problems, not the least of which is catastrophic tank failure.


i am going to put it on the front too, tank is in wall and the opening starts 2" from top of tank so it would be hidden from view.

the cut off switch is a good idea... reccomend a switch I should get? thanks

adidas
11-14-2006, 01:54 AM
I have used a CPR overflow for over 2 years now, it has worked great. It does require some maintainence ie. replacing the siphon hose and cleaning the pump. IMO these devices get a bad rep. our systems require attention almost everyday, to me it is nothing to check and see if the overflow is functioning properly while feeding or dosing.

the thing is, it was working fine... we cleaned the tube and it was working and for the 3rd time this week it flooded :(

beaker020
11-14-2006, 04:32 AM
The Madison M8000 is the standard float switch used by many. I special ordered one at Acklands-Grainger a few years back, cost me $20. You can pick up similar ones on eBay periodically for much cheaper. This site http://www.aquahub.com/store/index.html has all the supplies and DIY info too. MAKE SURE you use a relay.

This application is identical to an auto top off system except you may need a higher power relay and you would reverse the float if you decided to put it in the sump.

You could design a latching relay setup to prevent cycling. Let me know if you need help with that. I could bang up a schematic if need be.

bassman
11-14-2006, 06:43 AM
beaker020 has suggested the exact float from the same site I bought mine from :mrgreen: Works like a charm.

adidas
11-14-2006, 06:05 PM
thanks

i think i'll get this one

http://www.aquahub.com/store/atoreadytouse.html

beaker020
11-14-2006, 06:29 PM
That controller is specifically designed as a top off controller only. It has 2 major drawbacks for your purpose. 1.)it has an audible alert when pump is active. Which for you would be all the time. This can be disabled by removing the speaker from the circuit board so not a real big deal. 2.) It has a "float fail-safe" feature which only allows the pump to run for 3min 45sec. It can be extended to only 14min. Which means, in your case, it will shut your main return pump off every 14 min. and will need to be reset.

This controller will not work for you. Find a simpler one or build your own. They are super simple.

adidas
11-14-2006, 06:37 PM
ok it won't work then i guess lol. i'd rather just order a unit and pay a bit more than build one.

adidas
11-14-2006, 06:38 PM
how about this one? http://www.marinedepot.com/md_viewItem.asp?idproduct=TZ4111

beaker020
11-14-2006, 07:00 PM
nope, same problem only worse. And Yikes! did you see the price of that? You are paying alot for optical sensors and dosing pump.

Think simpler. A quick google search turned up this for tank mount:
http://autotopoff.com/products/ST1/index.htm
or this for sump mount:
http://autotopoff.com/products/SS1/index.htm

beaker020
11-14-2006, 07:05 PM
to prevent cycling you can add the $20 reset switch upgrade. Highly recommended

Dale
11-14-2006, 08:27 PM
On another tack...
Have you considered mounting your return pump intake closer to the surface of the sump waterline?
When I built my 75G. tank I calculated 1 1/2" of space between my overflow and the top of the tank. That equals 5.5G.'s before it over flows. In my sump I calculated that 2" of water equaled 5.5G.'s so I set my pump intake at 2" below the sump water line.
If the overflow plugs the return pump will run dry before it floods the tank.
There is a trade off between flooding the floor and burning out the pump but the water damage from a leak on the 2nd floor outweighs the cost of the pump.
________
F11 (http://www.cyclechaos.com/wiki/Kawasaki_F11)

pandafishowner
11-14-2006, 08:47 PM
there's water damage in the basement from it. it floods in the rooms upstairs and then comes and floods my daughters room downstairs.

fkshiu
11-14-2006, 09:22 PM
I plan on simply using 2 HOB overflows - a Lifereef and a cheaper Hurricane as a "backup" (although both will end up flowing about equal amounts).

I'll be using an Eheim 1260 as a return (~450 gph at a 4' head) so either overflow can handle the load even if the other is completely shut-down (Lifereef 600 gph max flow, Hurricane 500 gph max flow).

Both overflows are the more reliable u-tube design and since I picked both up used, cost is very reasonable for the resultant peace of mind.

adidas
11-14-2006, 10:32 PM
On another tack...
Have you considered mounting your return pump intake closer to the surface of the sump waterline?
When I built my 75G. tank I calculated 1 1/2" of space between my overflow and the top of the tank. That equals 5.5G.'s before it over flows. In my sump I calculated that 2" of water equaled 5.5G.'s so I set my pump intake at 2" below the sump water line.
If the overflow plugs the return pump will run dry before it floods the tank.
There is a trade off between flooding the floor and burning out the pump but the water damage from a leak on the 2nd floor outweighs the cost of the pump.

thats a great idea. thanks