probably a stupid question @ rr systems

[rfdoc]

My tank is not drilled and I haven't had the luxury of seeing that many saltwater tanks, especially RR systems. I don't get it - how is a tank that is drilled less likely to cause a flood than one with a HOB overflow? The tank has holes drilled in the bottom of it, how does the water not flow out when the return pump loses power?

 

[Shooter7]

When holes are drilled on the bottom, they should be surrounded by a leak-proof overflow area that extends up to the surface of the water. Additionally, you usually have plumbing that goes up to near the surface as well, so if you lose power and you have some drainage continuing, it only goes to about the level of your plumbing opening then sucks air and stops.

 

[werkkrew]

If an overflow box loses siphon there is a possibility your pump will continue pumping until the display overflows.

There are overflow boxes which won't let this happen, and, you can design your sump to limit how much water your pump has available to it, to get rid of this problem.

If you are extra paranoid, like me, you might put a small float switch on your display to turn off the main return pump if the water level gets too high.

 

[rfdoc]

I think I get it now thanks Shooter, someone showed me a picture. The only part I saw before was the black part you see from the inside of the tank. Since there are holes in the plastic at the top, middle, and bottom I didn't understand how the water doesn't fall out of the tank all the way down to the bottom holes.

 

[divemonster]

<a href=showthread.php?s=&postid=11605610#post11605610 target=_blank>Originally posted</a> by werkkrew
If you are extra paranoid, like me, you might put a small float switch on your display to turn off the main return pump if the water level gets too high.

Excellent idea! How did you put it all together? I have an HOB tank someone gave me and I'm a bit worried about spillover.

 

[werkkrew]

You get a switch from autotopoff.com or anywhere really, mount it to the display, set the depth where you want it, and plug the return pump into the cord.

The return will only go off if the display water level sets the float switch off.

 

[rfdoc]

Could it be done the other way, could you set a switch in your sump and if the water level goes below that line (ie the point where there would be too much water in the display and start to overflow it) the return pump would be cutoff?

 

[oldschooldino]

From AutoTopoff.com:


"Reverse Operation -
The controller turns the device off when your water level is low. The device will be powered when your water level is high. To enable this mode of operation, remove the plastic retaining clip that holds the float on and reverse the float so the magnets inside the float are on the bottom." HTH

 

[werkkrew]

Usually what you describe, Rfdoc, is how youd normally set up an auto topoff, because when your sump level gets low that is usually due to evap, not a loss of siphon.

 

[oldschooldino]

werkkrew - With a standard auto topoff, when the water level gets low, the switch would power on your top off pump. I believe what rfdoc wants is when the water level gets too low in the sump, the return pump powers off.