Plumbing Questions (Diagrams Included)

[unclegorb]

So, I've attached two diagrams of what my overflow and return setup will look like and have a few questions:

 

01. Is it ok for me to just run a 3/4" line into my 1" refugium bulkhead with no attachment? making sure to feed enough line into the intake so it wont come out...or adding an o-ring or something to just keep it in place.

 

02. Is the placement of my 1/2" check valve ok? or would it be more effecient to buy a threaded valve and put in between the ball valve and the 1/2" slip insert?

 

Thanks guys...any other suggestions or comments are gladly welcomed.

 

 

 

[Stephensx04]

I would say that would work fine. Except I would put a syphon break in the return line just below water level. Should never rely on a check valve to keep water from back feeding into sump when turned off. Also make sure your sump can handle what drains back.

[jeremai]

agreed, don't use the check valve. as for the drain, it should be fine just resting in the bulkhead, as long as it's in far enough to prevent any splashing. too many restrictions on the drain, though; either hard plumb it with 3/4" PVC, or look into using spaflex.

[markandstaci]

Setup looks nice. One thing I might change would be the check valve. There is no such thing as a 100% reliable check valve... a safer option would be to limit the depth of your return fitting in the tank. In other words, make sure your return pipe is discharging only about 0.5" below the surface of your water when the pump is running and the tank is draining back to the sump. That way, when power goes off, the only water that returns to the tank is the water in the return and drain pipes and about 0.5" of tank depth that has been back-siphoned into the tank. When the water depth in the tank is drained below the end of the return discharge fitting (i.e., an air gap), the tank will quit back-siphoning into the sump.

 

The problem with check valves is when people rely solely on them for back-siphon protection and then use deep tank returns or maybe have equipment (reactors, etc) placed above the level of the pump. In this case, a lot of water can back-siphon into your sump. Basically, any water that has a path to your sump will make it there and it will overflow. And if the check-valve becomes obstructed or has experienced buildup of materials or has warped and fails... it's not good. The air-gap siphon break is fail safe and will eliminate your need for the check valve. The advantage is it would be cheaper (no need to buy check valve), less plumbing maintenance (check valves need to be checked, cleaned, etc), and you will reduce head loss through the valve (more flow from the same pump).

 

Another comment might be made on the ball valve for your return pump. A gate valve would be ideal because it is more efficient and easier to tune than a ball valve (ball valves are more like on-off valves than tuning valves). But to be honest, gate valves are a little more expensive and maybe harder to find and you probably won't be sacrificing much by using a ball valve.

 

Also, when you get tubing, don't go with vinyl. I made the mistake of using it when I had to replace tubing on my Rena XP2/3 filters (FW cichlid tanks) because it was the cheapest option. Well, it didn't open up and resulted in a lot of backpressure on the filters and reduced the flow rate to almost nothing. The vinyl isn't rigid enough and when the pack it they flatten it out and kink it up and the shape never returns to it. I ended up replacing the vinyl tubing for braided PVC and it was minimally more expensive and many times better.

[unclegorb]

what about the plastic clamps...if I use braided pvc will I need to switch to metal clamps?

[markandstaci]

what about the plastic clamps...if I use braided pvc will I need to switch to metal clamps?

 

I use stainless steel clamps, not sure about plastic. Probably will be okay.

[C-Rad]

I've read the often repeated advice "only use plastic clamps" and wondered "why?". Sure, if the clamp gets salt water on it, it could rust, and if that rust got into your sump/tank, then you could have a problem. My clamps never get wet, and aren't mounted where rust from them could contaminate my water. I think the main reason for that advice is because you can easily over tighten a metal clamp on a plastic fitting, and crack the fitting. That's impossible to do with a plastic "zip" type clamp. If you're careful not to over tighten the clamp, and you know it can't drip rust into your system, then I think metal clamps hold better, and are a better choice.

[C-Rad]

From your description of the parts it sounds like maybe you are planning to clamp tubing onto slip fittings. That's not a good idea, although it can work. Barbed fittings are made to be used with flexible tubing, like vinyl, and will seal better than the smooth surface of a slip fitting will. I've never used flexible PVC, but I wonder if it is safe to use with clamps, or if it is designed to be used only with glue, like pvc pipe (find out before you use it).

 

when you get tubing, don't go with vinyl. I made the mistake of using it ... it didn't open up and resulted in a lot of backpressure on the filters and reduced the flow rate to almost nothing. The vinyl isn't rigid enough and when the pack it they flatten it out and kink it up and the shape never returns to it.

I've found that when buying vinyl tubing off of a reel, the tubing near the center of the reel is often flattened, but the tubing near the outside of the reel is typically not flattened, so just find a length of vinyl tubing that has not been flattened and you should be fine.

[oogie]

Looks good! Just 2 little things.

 

I would attach ball valve not directly on the pump but out of the water so when i need to use it i dont need to dunk my hand in the sump.

Also like others mentioned, i would get rid of check valve and just put very small hole just below the waterline on return. Should work as siphone breaker

[markandstaci]

... put very small hole just below the waterline on return. Should work as siphon breaker

 

Very small holes can clog. This still isn't 100% fail safe. The only failsafe method is making sure you develop an air gap after minimal backsiphoning has occurred. And I would still recommend braided pvc over vinyl. It will hold its shape without pressure whereas vinyl won't. The pressure required to "inflate" the vinyl hose results in decreased flow. I HIGHLY HIGHLY HIGHLY recommend using braided pvc.

[unclegorb]

well, i've made some adjustments to the return plumbing based off of the input given. Have a couple more questions and an updated diagram...

 

- Would it work to hard plump the water pump with a pvc tube > elbow > gate valve (see diagram). This would be to keep the gate valve out of the water? Then the rest would be braided PVC tubing...

 

- If I use braided pvc how would I connect a return? Could I just use a hard PVC elbow to hang over over the tank "lip" and then plumb some Loc-Line into the elbow? I haven't seen any manufactured returns that would accept a braided pvc line.

 

Thanks everybody for the suggestions, its very much appreciated.

 

 

 

[markandstaci]

Hard plumbing will work. Use barb fittings with braided PVC. You can find barb/FPT fittings:

http://flexpvc.com/cart/agora.cgi?product=...rb-Fittings-FPT

 

You could use this for your return:

http://www.marinedepot.com/U_Tube_with_Dir...-FT0001-vi.html

It already has the barbed fitting and the directional pipe.

 

Otherwise, looks good!

 

Edit: Have you considered hard plumbing a Tee into your pump output? That way you could have a way to move water to your refugium, through a reactor, etc. You would need another valve so you could turn the tee "on" or "off", but this could be a ball valve since you won't need to tune it like you would the display return.