Sump return check valve?

TinyChocobo · May 22, 2016

Currently I'm only running a fairly new 29 Gallon DT on day 11 but we are planning on going 75+ within 6 months.

I have been doing a lot of research before setting up a sump. I'm fairly certain I'm going to build the baffle system in a standard tank and whatnot.

I've been looking into return pumps as this setup will be about 12 feet below the bottom of the display tank.

I know I need enough pressure to push the water up that height but I've also been thinking about back siphoning should I need to shut the return off for any reason.

I could put a hole in the return just below the water line to cause it to pull air instead of water if power failed but I would much prefer to just keep the return line primed and the sump not overflown.

I know on my sump pump in my basement I have installed a check valve to prevent back flow. Any reason not to do this on a sump return line?

I want to be able to lose power without worrying about things overflowing.

I also thought about perhaps a normally closed solenoid running on the same power source as the return pump. I already plan on running that on an Apex controller if I can so if my water detector goes off it can shut off the return and close the solenoid.

redfishbluefish · May 22, 2016

It's my opinion to avoid check valves at all costs....with saltwater, they will fail rather fast. Best to have a siphon break and the volume in your sump to accept that amount of back water.

dbrewsky · May 22, 2016

My view on this is that your sump should always be able to handle the volume with surplus room in case of power outage or emergency. That being said I installed these check valves in my system for peace of mind and as a extra redundancy: http://www.bulkreefsupply.com/georg-fischer-wye-check-valve.html

My reason for doing so is again mainly for redundancy in the event that a return nozzle was moved lower, which would be a rare occurrence. Also, it makes everyday maintenance and feed modes easier since the water level is only dropping to the bottom of the overflow teeth instead of all the way down to the return nozzles before suction is lost. This prevents excess spray and air being pushed into the tank as the return lines purge air upon start up and reduces the time it takes for the system to return to normal operation after the return pump is shut off. I also don't like drilling siphon breaks because they create some noise and salt creep from water exiting the siphon break during operation. They do have the slight chance that the small diameter hole could clog with salt and prevent a siphon from breaking. I personally have never had this happen but have seen salt buildup in proximity to the siphon hole.

I do find these check valves more expensive than other options, however they are much more reliable compared to the flapper-type models and a huge plus being they can be disassembled for maintenance. I have noticed that these have a much more positive engagement when flow is cut versus the flapper type models and the design seems to ensure a better o-ring seal than the flapper valves. A lot of the failures seen with check valves come from lack of maintenance; this is especially true on valves that are difficult to clean and inspect. Like anything in this hobby, lack of proper equipment care will over time cause failures or reduced performance.

AZDesertRat · May 22, 2016

There are no reliable check valves for aquatic use , you are kidding yourself. You could have cleaned them 5 minutes ago but that will not stop a piece of food or anything from catching on the valve seat and preventing it from sealing. If it makes you feel good, go for it but it is a false sense of security.

TinyChocobo · May 22, 2016

Well you don't know until you ask... I have no issues having extra volume going unused in the sump but I was just trying to get the max out of everything I can.

I've honestly just never had/used a sump before - never really saw the point with my fresh water tanks.

dbrewsky · May 22, 2016

hey don't sweat it there are a lot of opinions and experiences in this hobby. The key is figuring out which ones help you achieve your goals. In your case where sump volume is not an issue in the event that power is out you really don't need to worry about one.

It will be beneficial in preventing drawing air into your return pipes as you mentioned in your original post. 12+ feet of air in a return line will create a ton of salt spray, bubbles, and general chaos in the display! I would say install the check valve I linked to to help prevent this from happening. The key is you are using it as a auxiliary feature to prevent the lines from purging not relying on the valve to prevent a flood. If the check valve fails it will not cause a failure. You can the. Address the check valve issue and it will continue to work as intended until the next time!

ngvu1 · May 22, 2016

I don't use check valve, but I do have a gate just in case I need to lock that up. If you decide to go this route, don't get the cheap pvc ball valve from HD. Get the double union ball valve for ease of disassembly and these guy are very easy to turn.
http://www.marinedepot.com/Slip_Dou...Valves-Plumbing_Parts-FT3913-FIFTVLTU-vi.html
http://www.marinedepot.com/Spears_D...PT_Ball_Valves-Spears-0S1233-FIFTVLBV-vi.html

ngvu1 · May 22, 2016

I only turn off the power heads when feeding. My return pump is not super strong and I only run it at 50% power and the it is are never off except water change or pump clean up :)

dbrewsky said:
My reason for doing so is again mainly for redundancy in the event that a return nozzle was moved lower, which would be a rare occurrence. Also, it makes everyday maintenance and feed modes easier since the water level is only dropping to the bottom of the overflow teeth instead of all the way down to the return nozzles before suction is lost. This prevents excess spray and air being pushed into the tank as the return lines purge air upon start up and reduces the time it takes for the system to return to normal operation after the return pump is shut off. I also don't like drilling siphon breaks because they create some noise and salt creep from water exiting the siphon break during operation. They do have the slight chance that the small diameter hole could clog with salt and prevent a siphon from breaking. I personally have never had this happen but have seen salt buildup in proximity to the siphon hole.
.

AZDesertRat · May 22, 2016

You don't need the check valve and you won't have air issues. When the power goes off the water will back siphon to the sump until the return(s) are exposed to air then quit. Key word here is exposed to air. Since the return is now above the water, when the pump starts again any air in the line will exhaust above the water level until water reaches the display again and starts filling the display again. Don't waste the money or time trying to maintain something that serves no purpose.

tjnorthdakota · May 22, 2016

I've always installed the true union clear check valves on any tank I've had or plumbed with no problems to date, that being said my sumps can handle the extra water if need be in case of failure. Way I look at it is if there is stuff big enough floating around in my display tank to clog it up I'm not doing maintenance on the tank like I should and I'd rather something get clogged up in the check valve than my return pump.

Salt-Lick · May 22, 2016

I don't use check valves either. I use gate valves so I can manually stop the water for maintenance. I would make sure that your sump can handle any back flow from a power outage. Easy to test. Fill your tank all the way up and let it overflow into the sump. Continue to add water to the sump until it's halfway full. Then cut the return pump off and let the water overflow into the sump. The water in the tank will drop just a bit until it's under the overflows. The sump should be almost full. Now mark the line where the water was prior to you cutting the pump off. That line on your sump is the fill line. Don't fill over the line and you will know you are safe if the power goes out. Hope this makes sense.

TinyChocobo · May 23, 2016

Makes perfect sense - I planned on setting it all up [empty, no fish or rocks or anything] and then filling it and testing modes of failure. I work in IT so we do the same stuff with networking/hardware. It all works great in theory but the real-world testing is where we find issues.

I'm still working out what I want to build into the sump, how I want to plumb it, etc. This has all been extremely helpful. I do plan on having manual valves in my lines for maintenance.