Hi, so I get everything about this method apart from how do you stop all the water that flows back into sump when return pump off, just going down the drain?
Continuous drip system
- Thread starter Farmerjones
- Start date
I would make sure to have an overflow leading to a drain in the sump to dump out any excess water
I get that bit and can see how would run under normal circumstances, how do you make sure you don't run pump dry when it restarts if all the "extra" water from display tank has gone down drain?
Is the sump on the bottom or top of the aquarium? The drip should always keep the tank filled. I would make sure the overflow is at the top of the aquarium to prevent it from completely draining out
You don't. In the design you're talking about it would just mean when the return pump comes back on you'll get a bigger water change than usual. Shouldn't be anything dangerous unless you've got a LOT of extra water going going into the sump and out the drain.
Some of it will. Your sump should be sized accordingly.
Not really. The water should still drip in at the same rate. But after a power failure, you would have a little less water in the entire system, until the level in the sump settlement chamber rises up to the drain bulkhead.
I use back flow preventers. They're not perfect but they slow the process WAY down in the event of a power outage or if the sump pump poops the bed. They look a bit like a rubbery coupling and they have an internal flap that goes one way. Pump on? The flap opens up in the direction of flow. Pump's dead? The flap closes and reverse flow is largely eliminated. My plumping is 1.5" PVC and I got my BF Preventers at Home Depot for like 15 bucks apiece, ballpark.
That's a key factor. Many of the sumps in use today are overly complicated designs that incorporate a ridiculous plethora of redundant baffles. Aside from wasting space and hindering access for cleaning, they also reduce the capacity of the final chamber which contains the pump. That's the point at which the overflow to the drain for the continuous drip system is located.
The smaller that pump chamber is, the more the water level changes in it as the tank drains down in a power outage. As that drain down water enters that little chamber...and is lost to waste through the overflow drain...the greater the chance that the pump will run itself dry when refilling the tank once power restores.
It is critical that the sump, and especially the final pump chamber, is large enough to allow for sufficient capacity to prevent this.
Check valves stop water from entering the sump by siphoning back down the pipe through which the pump feeds the tank, but they cannot stop the water that enters the sump in the "correct" direction, i.e. through the weir or other overflow. The water inlet to the tank from the sump should be either slightly above water level in the tank, or must have a hole drilled at water level, to break the siphon action and prevent any backflow at that point.
Last edited:
This is a very rough diagram of a tank with sump and continuous drip. Of course the final thing should be more refined, maybe with a herbie after the weir, backflow check valves and whatever else.
The important thing is the settlement chamber has sufficient volume. In a power cut, water will inevitably drain from the overflow chamber, and possibly from the pump, into the sump, and water will be lost down the drain from the top of the settlement chamber. There should be enough water left in the settlement chamber, above the pump intake, to replace the lost water in the main tank when the power resumes. It time, the water level in the settlement chamber will rise up to the maximum again.
The drip functions always, and helps to agitate the surface for oxygen when the power is off.
The drain at the top of the settlement chamber should have a U bend or a loop, not just so that no smell comes up from the main drain, but it also slows down the loss of water during a power failure.
The important thing is the settlement chamber has sufficient volume. In a power cut, water will inevitably drain from the overflow chamber, and possibly from the pump, into the sump, and water will be lost down the drain from the top of the settlement chamber. There should be enough water left in the settlement chamber, above the pump intake, to replace the lost water in the main tank when the power resumes. It time, the water level in the settlement chamber will rise up to the maximum again.
The drip functions always, and helps to agitate the surface for oxygen when the power is off.
The drain at the top of the settlement chamber should have a U bend or a loop, not just so that no smell comes up from the main drain, but it also slows down the loss of water during a power failure.