Overflow to sump

I am attempting to build a 10 gallon sump for a protein skimmer. My problem is that my tank is not drilled so I was told to get an overflow. I am trying to understand how all this works. So far I see the overflow as draining water from my tank to the sump. I than need to buy another pump to put in the sump to return the water back. But I hear all these warnings about if the power goes out the sump will over flow. So i am planning on filling up the sump just enough so if power does go out and the overflow box is drained the sump will accomodate the excess water. Am I on the right track?? Also what if I get two pumps one in the tank to pump water to the sump and one in the sump instead of an overflow??Any suggestions on a certain brand or type of overflow box?
thanks

 

Sounds like your on the right track. Trial and error is about the best approach. I'm about to order one of these Hang-on Continuous Siphon Overflow 600 gph w/ Bulkhead - 704007 myself. Basically the pump that is in the sump and the over work together. The overflow will only allow as much water through that the pump puts back in. If the power were to go out you need enough space in the sump to allow for the water that is "en route". Attaching the primer tube to a power head is suppose to reprime the overflow when the power comes back on. Supposedly it works almost flawlessly and I'm soon to find out.

Hope that helps.

 

Superclouds is right about how they work together(most of the time). You just need to make sure that the overflow and the pump are in the same gph range. As for the idea of having two pumps, I dont see the point. Why buy another pump when you can achieve the same with gravity. I hope you realize that when the elec. goes out, it doesnt mean that your whole display tank is going to drain into the sump. Just set up your plan, plug it in, then unplug it and see what happens. If you see that your sump is going to overflow, plug the pump again and go with plan B. Like Superclouds said, trail and error. I hope this has helped you, Luna.

 

First those overflows where you need a powerhead to continually pump bubbles out of the overflow box are TERRIBLE. It WILL fail eventually. Get a regular amiracle type overflow box with a j/u tube and be done with it. I have used them for years and have never had a single one fail unless the fault was mine because of carelessness. Letting snails or other creatures get into the box/etc.

The problem with water level in the sump after power failure does not come from the overflow box but from the water line returning the water to the tank. The overflow only has several cups of water in it at any one time and since it skims water from the surface of the tank, once the power goes out the water will stop entering the box quickly. The return line however will siphon water back to the sump as long as the return is under water. You need to have it either placed just under the surface of the water so if the power goes out, or the pump fails, the water level will drop and air will quickly enter the line and break the siphon or you have to have a siphon break installed...and maintained...so that it will cut the flow immediately. I would do both. You can try a check valve. They work for a while, but they will fail as well too. You just don't know when. Usually when you go on vacation.

If I were you I would go with as large a sump as I could fit under the tank. Now tha you have a sump the water level will now be rising and falling in there and not the main tank. I don't know how large your main tank is, but with the added surface area of a sump, and greater water agitation, you're going to get more evaporation. I think you'll find with a ten gallon sump you will have to constantly be on top of the top off water or your skimmer/return pump will constantly be cavitating. A larger sump also helps to accomodate the water that will drain back into it.

Figure it this way. A ten gallon tank doesn't really hold ten gallons. Figure 9, though I am just guessing. Now you have your skimmer and your pump, figure they displace a half. Now you have 8.5 You don't want it full because you need to accomodate water that will siphon back. Without knowing the size of your main tank, let's figure on 2 gallons conservatively. That leaves you with 6.5 gallons and will fill your sump to the tippity top in a pump/power failure. 1 gallon for evap a day? That leaves your ten gallon tank running at half full by the end of the day? Can you see your pump and skimmer running in a half full tank for more than a day? Cause remember the next day you'll have another 1 gallon evaporated, leaving 4.5.

 

I have this overflow and use a Toms Aqua Lifter pump to keep the siphon running. It works great, not one single problem with it, with a total cost of 40 bucks!

 

As with anything else, ymmv. Why bother with a piece of equipment that needs another pump to make it work correctly when you can get an overflow box that needs to additional equipment to function. More equipment means more places for something to fail.

 

To add some pics to this I get into it about 5 posts down here:
http://www.3reef.com/forums/new-hobby/how-make-sump-31712.html

 

overflows are bad

If the tank is not already up and running. Drill the darn thing. Overflows suck. If you have a hood on your tank then 98% of the overflows created will not work. I am using a J-tube with an aqua lifter pump. It sucks. I get air bubbles in it every 4-5 days. I have so much throughput the bubbles do not rise to the top. I split the input to the lifter pump into two lines and now a few air bubbles are pumped out. But still I have to manually play with the lines to get it to work. The tube fills with algae and you have to clean it about once a month.

Try to avoid overflows at all cost!

I am too afraid to drill my tank otherwise I would have. I might start a new tank and move everything over? Note: new tank will be drilled!

Zak

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55 Gallon Glass Aquarium; 20L Sump; 1-UV Sterilizer-(sump); Coralife Super Skimmer 65(sump); 260 W Compact Fluorescent Lighting; 2-Power heads; 20 lbs live rock; 2-Ocellaris Anemonefish; 1-Fire Goby; 1-Pacific Blue Tang; 2-Banggai Cardinalfish; 1-Green Mandarin; 1-Singapore Angle; 20 Blue Hermit Crabs; 8-Turbo Snails ; 2-Bubble Anemones; 1-Seabay Anemone; 1-Yellow Hand Coral; 1- Polyp; 8-Green Strip Mushroom; 2-Sandsifting Starfish;