Above tank sump

[Rybren]

I'm currently running a 30 gal SW tank with no sump or fuge, but I'd like to add one.  As I see it, I have 3 options available to me when considering the sump:
1.  Drill the tank and place the sump below the DT.
2.  Get an overflow box.
3.  Place the sump higher than the DT, pump water to it and let it gravity feed back to the DT.

Option 1 is discounted because: I really don't want to break down the tank to drill it and my beautiful and charming wife (she might be reading this) doesn't want me to get a bigger and pre-drilled tank (yet)

Option 2 is discounted because: I'm afraid of flooding (and the subsequent inevitable yelling and screaming coming from my beautiful and charming wife).  I know that a number of OVAS members have used overflow boxes for years without problems, but Murphy REALLY likes me and comes to visit as often as possible.

This leaves option 3.  Because of where my tank is located, I could easily set up a sump out of sight and just slightly higher than the DT.  There would be a 3-4' run from the DT to the sump.  I was thinking of using an MJ 1200 to provide the flow from the DT to the skimmer (Octopus Recirc 110) which would dump into the sump.  The water would do its thing in the sump and then gravity flow back to the DT.  If I planned things properly, I should be able to set it up so that the risk of flooding is marginal (a line could burst or a bulkhead on the sump could leak) I realise that the MJ 1200 doesn't put out a ton of flow, but as I understand it, I don't need a lot through the skimmer or sump (I'm currently feeding the skimmer with a MJ 600) There would be minimal head to push against (6-8").

I have seen discussions regarding this type of setup on other forums, but I was wondering if anyone here has tried it or can point out a door for Mister Murphy to open and come visiting - again.


Cheers

[FocusFin]

Hey Jerry,

It sounds like a good plan. If you find the flow is not strong enough from the Maxijet you can always drill a hole or two or three in the impellar cover.

Good luck.

[Consigliere]

Really the same sump principles apply here in terms of fail proofing your system.  You will want multiple overflows in your sump in case one gets plugged and its much easier to silence your system this way.  The other thing you will have to make sure is that your inlet in the sump from the DT is close to the water surface or you will have to put a siphon break on it to make sure you don't siphon off all of the sump into the DT during a power outage.

[Rybren]

Mike & Consigliere (you've got to be a fellow pisan with a handle like that )

Thanks for the thoughts.  I'm still in the planning stages but I hope to move to the execution phase the next time my B & C wife goes out of town. (Yeah, I know, it may be the cause of my execution, but I have found that it is sometimes easier to plead for forgiveness than it is to ask for permission.)

[FocusFin]

Mike & Consigliere (you've got to be a fellow pisan with a handle like that )

Hey, Tom Hagen was irish in the Godfather .

[Hookup]

Jerry,
  There are numerous advantages to an above-tank sump, but for most people there is no practical way to put a sump over their tank so it is not commonly done.  It's been argued, successfuly, that a fuge should be mounted over the display tank (DT) and use gravity to return the water directly into the DT thus ensuring the best copod population arrives in the DT itself.

  I really like the idea of having all of your DT water being pumped into the skimmer regardless of how/where you sump is located.  So that is another big plus for your concept/design.

  The down-side to your design is the lack of surface skimming from the DT.  Most of the nasty oils, skum, and general bio-load gunk that cannot be broken down by your CUC floats to the surface of your tank and makes that film / oil-slick look on the tank.  This is especially noticeable in tanks that do not have any circulation water breaking the surface of the tank... you can see stuff oozing around on the surface.   

  It is possible, to create an internal overflow box, that has your lift-pump in it to create the surface skimming effect.  This would be 100% safe, because there are no syphons involved, you're just "selecting" the top layer of water to get pushed up to your skimmer/sump.  You'll need to have some kind of flow-control on the lift-pump so that you are not sucking the overflowbox dry.  You'd also want to have the greatest possible amount of surface area being skimmed...

  It at all possible, maybe you could create an over-flow box that runs the entire length (or most of it) of your tank.  It would only have to be 6-12 inches deep, in fact you could even make it 2"deep on one end, and 8"deep on the other (where the pump is) if the mood hit you..  All you're trying to do is get a box full of surface water.  Then have the lift-pump take that water up to your skimmer/sump.

Anyhow, something to think about as you start to plan.

[Rybren]

Tim,

Great thoughts.  I was thinking of building an internal skimmer box to feed the skimmer anyway - I find that with my current setup, there is almost always a film on the water surface (the only time that there isn't is when I put a new piece of Poly-Filter in the Aqua Clear HOB filter)  I only use the HOB for Poly-Filter and occasional carbon.

As suggested coast to coast style box might just do the trick.

Thanks & Cheers

[Zzippper]

I have found that it is sometimes easier to plead for forgiveness than it is to ask for permission.

Hmmm - you may have something there... (mental gears turning    )



Z

[Sharbuckle]

its funny i was just thinking about doing this with my 20g the other day, but im just making a simple 2.5g fuge over my tank, still not sure how im going to do it though, so this is giving me ideas

[Severum]

I tried this for my 33 gallon a while ago. The problem I faced was that the glass on these smaller tanks was too thin and cracked when drilling.  It would be very difficult to get two holes on one side for redundancy unless its done on the lengthwise side.

I put the idea on the shelf and ran into Super Pet going out of business and ended up with my 120.

[Consigliere]

Probably the issue with the cracking was that the glass was tempered.  I drilled 2 holes side by side in a 20G recently and had no problems at all.  A lot of smaller tanks are all tempered now though because the glass can be thinner and maintain its structural integrity.  Saves shipping costs.

Anytime you are planning on drilling if you cannot tell 100% it is tempered or not then you are risking the tank.