Do you use check valves?

[wachuko]

Do you have check valves to avoid the tank from draining a few galons into the sump when you turn off the pump during water changes?

I have noticed that when I turn off the pump there are at least 5 galons that come down via the return pipe (pipe where water goes out into the tank when the pump is working).

Currently it does not cause a problem since the sump can take it...

Just wondering if others have the same issue and did something about it.

 

[Shooter7]

Ball valve just above the return pump. Can be used to control the flow from a pump if you want to use it for that as well, but I use it just for your above scenario. My sump can handle the backflow from the returns until the water gets down below the anti-siphon holes, but I like to keep the level where it is in the display and sump while doing a water change, so I just crank the ball valve shut at the same time I'm shutting down my return pump and I don't get the backflow.

Just remember to open it back up when you start your pump back up.

 

[sage_commander]

I don't. I have my return nozzle just below the level of the overflow box. Also, the "full" line on my sump is such that when it does backflow, it's well below the level of danger.

I've not heard good things about check valves. They can get clogged with sand or a small critter. Don't count on them.

 

[wachuko]

Cool. Thank you for the responses. I will get a ball valve instead.

You can tell there was not too much planning when I put this together... learning for when I setup the next one...

 

[cardiffgiant]

I use one, but only to break the siphon from my back flow faster. My check valve alone would still allow water through.

 

[AZDesertRat]

Check valves are mechanical devices and fail. They also require maintenance and cleaning which we all seem to forget in time.
The best method is keep the returns close enough to the surface only a calculated amount of water backsiphons before it breaks suction. This along with always maintaining proper room in the sump at all times is the only sure fire method. Drilled holes and check valves can fail immediately after cleaning, all it takes is a small snail or scrap of food, algea etc.

 

[snorvich]

Agree with above. ^ BUT I do use them on my ozone generators as a safety precaution.

 

[realest]

Me too me too,

I use them as a pre-caution. Better to be safe then sorry. Can't picture how is gonna be with 55gals of saltwater on my floor

 

[AZDesertRat]

If your return is designed and constructed properly you will never ever have any water on your floor. Nothing takes the place of a physical air gap for both reliability and ease of use. Nothing to fail, maintain or replace ever.

 

[dsn112]

<a href=showthread.php?s=&postid=11663130#post11663130 target=_blank>Originally posted</a> by AZDesertRat
If your return is designed and constructed properly you will never ever have any water on your floor. Nothing takes the place of a physical air gap for both reliability and ease of use. Nothing to fail, maintain or replace ever.

Can you explain how you acomplish this

 

[Macimage]

I agree that check valves and drilled holes have too much potential to fail. It is far better to design and plumb your system so that all the backflow will be contained in your sump.

Joyce

 

[AZDesertRat]

Two simple things.
1. Keep your returns close to the surface. With returns up high its easy to calculate the total volume of water that can possibly backsiphon down to the sump in a power outage. My returns break suction the same time the overflow teeth become exposed so using Length x Width x 1" depth (the distance the water in the tank drops in my case) divided by 231, I know I will siphon 4.67 gallons into the sump worst case. Its usually less than this but thats worst case.

2. ALWAYS maintain at least that much room in your sump at all times. I use a Sharpie to mark the level on my sump and never ever fill past that point even when topping off. My sump is a 30G long so I always keep 2.5" of space free to contain that 4.67 gallons. To be even more conservative I actually keep 4" available but have never needed more than 2" to contain backflow.

My returns are LocLine through 1" bulkheads in each upper back corner and always kept so the ends are no more than 1" below the water level even when aimed down or to the side. The overflow is an internal center overflow with a Stockman standpipe so it does not drain completely.

 

[dsn112]

I see, I am doing all of that already. So I have nothing to worry about. I Use a stand pipe 2" below water level, I have my return locline the same way and have room for about 13 gallons in my sump so I could never overflow onto the floor.