two 10 gallon tanks as a sump??

hey all,

I need some advice here. I have very limited space under the tank for a sump. It's 20 wide x 18 deep x 26 high.

I'm thinking of using 2 10 gallon tanks (20x10x12 each) as my sump....the first tank would be where the tank water comes in, and houses the skimmer and heater, the water would then be siphoned to the second tank which would be the return section.

would the siphon keep the water level in both tanks even?

if there is a power outage, i would lose ~6 gallons from the tank into the sump, so if i kept a running level of 6" of water in the sump(s) i should be ok...

Also, could i just use the skimmer to pump the water into the return tank? the problem i see with this is, if there is a power outage, the rear tank would overflow for sure...

any advice is appreciated, see below for my quick sketch..:-/

 

yes it would but water changes would be a beach(haha im too funny), you would have to restart the siphon every time you do them.
for a better system drill both tanks and have pipe connecting them.

 

what if i have the siphon going to the bottom of the tanks?

any immediate downfalls to this setup you see?

 

nothing beyond what i said before, maybe the tube could get clogged if you have sponges that aren't secured

 

like sostoudt said....def. drill the tanks and connect them that way. far less potential issues to deal with. Of course you could also take a stab at custom building your own sump to the size you need.

 

Drill Baby Drill

Drill the tanks and plumb them together with PVC. That's what I did. Mine are side by side though. You can see some pics and read a description here. Paul's Reef: Where have I been?
You don't want to worry about a siphon if you don't have to. I was too afraid to drill my DT due to the cost and risk. 10 gal tanks cost like $7 at Walmart. I broke the first one I tried. No big deal.

I used a valve to adjust how much flow goes into each tank from the DT. You can see just a small piece of the green valve in the pic below. Close the valve and all water goes into the sump section. Open it all the way and 99% of it goes to the fuge first. This why I can fine tune the flow and have a lower flow into the fuge and higher flow into the section with the sump, skimmer and heater. Some people recommend putting the fuge after the skimmer so your pods don't get skimmed out. In my setup the fuge is before the skimmer. My tank is full of pods so I don't think its an issue.


Here is what the sump section looks like. I use a corallife float valve for gravity top off.

 

How large is the main tank ? I ran a 100 Gal acrylic sps tank for 7 yrs with a 10 gal sump.. I run about 4" water level . But you best drill the main tank or get a good HOB overflow then you can regulate to overflow line and power off drainage amount to sump limit.

 

disilowka3: thanks for the advice, i looked into building an acrylic sump, but a 4x8 sheet is $180 here...so it just doesn;t make sense...

pgreef: so how does the fuge send water to the sump tank? are they both on the same level? is the water the same height in both tanks? when you have evaporation, do you only see the water in the return section drop?

tangster: my display is a 150 gallon, and it's not drilled, i have a cpr overflow with a siphon pump on it. this is all new to me still, i have not setup my tank yet. with the limited amount of space i have under the tank, the biggest sump i can get in there is the 20 gallons...i was planning on having 1" of water over the intake for the overflow, which would limit the water drained to the sump at 6 gallons...

is your tank drilled? how did you regulate the amount of water that would drain in the event of a poweroutage??

 

The water flows into the sump section from the fuge because new water is flowing into the fuge and skimmer section. The water in the skimmer section and the fuge are at the same level. The level is set by the baffles between the skimmer section and the sump (the return section). Since the sump section is lower than the fuge/skimmer section water flows into it as new water comes into the fuge and skimmer sections from the DT.

If I didn't have the auto top off (ATO) then the water would drop only in the sump (return) section due to evaporation. This is because the level in the skimmer and fuge is set by the height of the baffles. So the sump is where the float valve for the ATO goes. As the water level drops the valve opens allowing water to flow in by gravity from the RO reserve water in the container on top of the sump. As it fills up the float valve rises and closes the valve. The level stays perfectly constant. The float valve is attached to a piece of acrylic siliconed to the glass. I drilled several holes in the acrylic so I could set the maintained water level in the sump. Here is another pic.


Very important. Your retrun plumbing from your sump to the tank will act as a siphon when the power goes out. You need to drill some holes just above the water line in your DT to break the siphon when the power goes out. You can also add a check valve in your return plumbing. Better yet, do both. You will also get some additional water flowing down from your overflow after the power goes out. All this water will fill up your sump. This is why the water level needs to remain low in the sump during normal operation. You need to experiment and determine what the max level in the sump should be and mark it so you don't forget. When everything is off and all the water has flowed down to the sump and reached equilibrium you can top the sump off with fresh salt water and turn everything back on. The water level in the sump will be at the maximum you should ever let it reach.