I've gone out of my way to setup all my electrical outlets, lights, tunzes, etc, on redundant circuits, and each outlet serves as it's own GFCI drop, so that loss of any one outlet or entire circuit won't compromise the system.

However, I've had a bit of a problem trying to figure out how to make my plumbing redundant. I'm not too worried about redundant pipes- if the PVC decides to burst, the ensuing leak would be the biggest issue. Rather, I'm thinking about redundant pumps.

In one scenario, you could argue two that two return pumps would be sufficient redundancy. Except that most poeople (including myself) only have one pipe returning to the main tank. And running two pumps at the same time is a waste of electricity.

So the question becomes - how do you have redundant return pumps using the same pipe?

I've seen a particular someone have two large pumps side by side. Both branching into the main return line. Both being fed by the same intake as well. There are ball valves on the "backup pump" and the main. If the main dies, turn the ballvalves on both pumps and plug the backup in. good to go.

I thought about that, but chances are that things will fail when I'm not around... Granted, it's ready to go, so that system is better than none.

check valves and a relay would work. set up the relay normally open so second pump comes on if power is lost to first pump.

If you have enough circulation in your main tank via powerheads or closed loop then it's not an issue. Keep a small minijet in your refugium and your good. Main pump fails, big deal you have circulation to the tank. A few days without a calcium reactor or skimmer isn't going to hurt anything.

Pretty much your only other option is running 2 return pumps all the time.

You branch the pumps together.

Both pumps are plugged in one runs as the main pump.

The other pump while plugged in is kept open with some type of circuit tied into the main pump and closes the circuit if the main pump de-energizes.

Not sure what parts you would need but I bet if you did the research you could find the parts locally and the wiring would be easy.

The tricky part is trying to monitor the pump for a failure. You would have to monitor the power load or have a flow meter trigger the relay. I simply put valves and unions directly at the pump to aid in swapping to the backup quickly. I plan to monitor any water temp variations (between tank and sump) via email alerts to alert me of a pump (or fan/chiller) failure.

I haven't had an Iwaki fail on me yet. 9 years running 24/7 on one tank via MD55.

JM

I have another theory/idea. Why not plumb 2 smaller pumps together (parallel to each other). Run them at the same time and if one fails you still have the other to drive your system (obviously size it correctly). I'd put visual check values inline for both so you can see if one is having issues. The probability of both pumps failing at the same time is pretty low.

Now if you were pretty @nal you could plumb one pump into one return and the other to the other return that way you'd have even more redundancy.

So what do you guyz think?

I might just go this route myself.

I was speaking to Chris about monitoring electrical outlets just the other day. I have an electronic circuit that can trigger on a pump failure. It might be what others want also. if you want to see the circuit i can send it onto you.

Simon- you may want to check out this site: http://www.flowdetector.com/

I found them a while back when considering this idea - there's both the circut and the flow detectors to tell when a pump isn't actually pumping. The thing that concerns me with just watching the line current is that the pump could be spinning but cavitating or something - a flow detector may be better...

If you have enough circulation in your main tank via powerheads or closed loop then it's not an issue. Keep a small minijet in your refugium and your good. Main pump fails, big deal you have circulation to the tank. A few days without a calcium reactor or skimmer isn't going to hurt anything.

And this is what I've got right now, so I don't lose too much sleep over it. My biggest worry is that something will either jam the pump or something else to cause it to overheat, or worse, start an electrical fire. Although I suppose I could argue that might lights are at a higher risk for that anyway... Oh well, it's fun to think about the problem...

Oh, Chris what about your chiller, how is that plumbed into your system. If you loose your main return pump how will your tank be chilled especially with those nice 1000 watters.

I agree, with kwl1763 with regards to the skimmer, calc reactor, etc.... you can live without those. Powerheads or C/L's are a must anyway so i'd expect they oxygenate your water in the main tank. Heat generated by show tank pumps and lights would be my next concern.

My chiller runs off the same pump as my skimmer (skimmer, then through chiller). But you bring up an interesting point. If my main pump cuts out, then the display tank will cook, since the controller for the chiller is on the chiller itself (it's all integrated... not my choice, but...). The temp cut off for the lights is based on sump temperature.


You know what might be the best solution in the end.... I could get one of those flow detectors and hook it up to my controller. If I didn't get flow for, say, 10 minutes, then shut off the lights, email me, send alerts, etc.... Ie- take a passive approach rather than trying to completely automate the solution.

;-)

nothing new, i have the same issue :-) dilema. I think i'm just going to keep kids. They are alot simpler.

Just put the temp probe in the display! Who cares what your sump temp is at!

I like your last idea best chris.

I would use 2 pumps and run them inline. Pump #1 feeds pump #2. If either pump fails the other pump would just pull/push through the other. Also, the pumps would run more efficiently, so they would run at lower than stated draw.

Caveat is 2 pumps though.

Chris, with your water volume, you don't need to worry about it. If the return fails, the tank should maintain temperature just fine. If it get a little too hot, your controller will kill the lights. As long as there's circulation in the display, you're okay.

Seems to me that pump 2s impeller would have alot of stress on it in this configuration. Maybe i'm wrong. It would be interesting to see they can be safely force fed. That would definitely be a good solution.