Refugium question

[epaz]

On my return line to my DT I installed a ball valve to help control flow/water level in fuge. My issue is to get the appropriate water depth for my skimmer to function I have to half way close that valve and it sounds as if I'm overworking my return pump. Is this an issue and if it is how do I resolve it? My intake into the fuge is open full bore.

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[LaWoWee]

Ideally, you want to have your skimmer on the drain side behind a baffle where the water level stays consistent and nevers changes. It will also serve as one of the first line of filtration defenses. Keeping the skimmer on the return side, you'll always have to worry about return flow rate and water evaporation.

 

[kdpuffer]

Like was stated above plus an addition. With the valve on your return hose I would install a T fitting or Y to split your return into 2 outlets, one to the tank and one back into your first chamber where the tank drains. Install a ball valve on both so you can get your desired flow nailed exactly. I say both because if you install a valve only in your return to the tank and allow the loop line to flow free you will have way less flow going up than you want. If you opt to run one valve put it on the loop line as this line will flow much higher due to less head pressure. The whole purpose of this is to allow the pump to run unhindered by back pressure meanwhile getting the max flow up to the tank.

 

[epaz]

Thanks all for the advice sounds like I have some plumbing to do

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[mr_X]

Actually, it's completely safe to choke back a pump at the exhaust port. It saves energy and makes the pump last longer. Hindering it with back pressure is good for it.

 

[kdpuffer]

My old return pump and years of knowledge with pumps and motors says otherwise. A pump/motor is rated for a certain load, less load is fine but overloading is not. I can't argue that some back pressure is fine but finding that balance can yield another trip to the store for a new pump. It's not typically the motor part of the pump that's the issue it's all the peices that hold it all in place. To much back pressure can and most likely will lead to a breakage of something, in my case it was the shaft the rotor spins on. In some cases the rotor will bulge/swell which is bad. A basic rule I follow with back pressure is if you restrict the flow and the pump gets louder then it's to much. My suggestion above is in regards to this. If you split the outlet you can fine tune your flow and not be concerned about back pressure issues. This is also a good way to run reactors FYI. Instead of adding another pump just t off the return and run it to your reactor.

 

[mr_X]

Google it if you don't believe me. Engineers would disagree.

 

[kdpuffer]

I didn't say back pressure is bad, to much back pressure is bad. Like I stated above, a motor and pump are rated for a specified load, exceeding that load is definitely bad. How bad depends on how much you exceed it. Everything is built to last based on a standard set for what it's application is whether it's an internal combustion engine, electric motor, even a simple shovel or your own body. Exceed the recommended ratings for those things and you will have issues.

 

[mr_X]

So, what is the recommended rating for choking back any given pump? I can't find anything on the net about that.

 

[kdpuffer]

What's the max rated head height of a given pump? That flow at max head would be what would want to keep the pump running at, restricting it more would create excessive back pressure the pump is not rated to handle. Every type of pump will vary aswell as variations based on the model and the designed purpose. A fountain pump for a pond could handle more back pressure than a typical pump used for aquariums due to they need that pressure to get the ornate spray pattern. It's all about selecting the right pump for the job and using it within the manufacturers recommendations.

 

[mr_X]

Cycle Stop Valves, Inc.