Sump Overflow Avoidance

[jesterns2]

The construction of my sump/refugium is complete. This Friday I plan on getting vinyl hosing and other plumbing parts that I will need. I will be using a CPR overflow box with a Aqualifter. I have done research on this subject but want to make sure I dont have any flooding issues or any others for that matter.

I have a 75g tank (120lbs Live Sand 130lbs Live Rock), 29g sump, CPR Overflow is 300gph, mag 5 return 500gph but with head loss im looking at no more than 350gph.

My baffles are 10" high, leaving me with enough room in the sump for 10.5g of water should I have a power failure. I don`t plan on putting the overflow any deeper than 1' below the surface because I do want to skim the top of the aquarium. In my aquarium 1" of water equals 3.74g and in the sump its 1.7g for every inch so I should be ok. Also I plan on putting two small holes in the return to break siphon a half inch below the water level and probably a ball valve so water can`t flow backwords.

Please tell me you`r suggestions I would greatly appriciate them, Thanks Bill

 

[bmiller1234]

How big is the return area of your sump? I just went thru this about 2 months ago, trying to go a touch budget and not drill and decided it wan't worth the risk.

You have to make sure that having the 1" in your display tank is enough room that if the cpr loses siphon that whatever pumps out of your sump doesn't overflow your DT.

I will tell you what everyone else told me.....if you can, drill the tank. Anyhting with a siphon means that theres the chance of losing siphon which leads to a flood. It cost me 140 bucks for 2 1" bulkheads and a 3/4 return with dual locline output drilled and installed at a LFS and now I have no chance or risk for any type of flood or overflow.

it was a small price to pay to not have to worry about flooring, carpet cleaning, your mag pump burning from running dry and well, most importantly my significant other screaming about 20 gallons of saltwater on the floor....

Good Luck

 

[NaClH2Opgh]

I have had the weir type and U-tube over boxes and both can be a pain with loosing siphon. I wish I would have drilled but with that being said I never lost siphon completely it would just get air pockets in tube or weir and slow the overflow down a bit. You look like you have the main points covered with the siphon break holes and room in the sump for the display tank to drain in the event of a power loss. IMO, if you have a the siphon break holes and room in the sump calculated properly there is no need for a valve (check valve). It's also just another thing you have to take apart and clean and worry when it will fail.

 

[cloakerpoked]

Buy a Tom's aqualifter, tap into the top of the u-tube, and have the aqualifter regulate the flow. I've got a picture here somewhere. It basically makes it operate on the same principle as the CPR overflow's. And I can promise you will never loose a siphon as long as both ends of the u-tube are under water and remain that way. It will mean either separate compartments or a standpipe of some type in the back end of the overflow box. A lot have a divider already.

As far as anything else, if you run the overflow box until it stops, then fill up the sump, and turn back on your return pump. Once the system equalizes, put a line at your water mark in your sump, and never go higher than that mark.

Now let me go get that picture here somewhere.

 

[cloakerpoked]

Been running for 2 years now with no overflow problems except once when the pump burnt out from fluxuating current during a very strange storm. All other outages this baby fires the overflow right back up.

 

[jimzin15754]

Im running basically the same system as you plan to run, my tank is a 90 gallon (same dimemsions except taller) and my sump is a 29, using a cpr and an aqualifter. Only difference is my baffles are only 7.5 inches high. My advise on set up would be to run on the dangerous side at first! Dont drill your siphon break untill your sure of your tank level. My cpr even with the aqua lifter will still fill with air over time if its level. I have it tilted approximately 1/4 higher on the vacuum side which raises the water level in the tank accordingly. my siphon break is 3/16 dia and 1/4 below water level. If you have any question in particular Ill do my best to tell you what ive encountered

 

[jesterns2]

Just thought i`d send an update on the sump. It`s up and running, no flooding occured so my marriage is safely in tact LOL!! I did have a little leaking from the bulkhead but I seem to have gotten that under control and also we had to use a piece of I believe 3/8 vinyl tubing to put onto my return and then put my 1/2 inch return line up into that. I did get some leaking from that but put a couple zip ties on and they seem to be doing the job. As it turned out when I cut the power to the system I still have 4 to 5 inches of room left in the sump before it would overflow.