Help! New tank overflowing when pump off.

[exnisstech]

If you have a check valve it’s not needed in my opinion. But you guys do your thing.

If you have a property sized sump neither is needed . Happy Reefing

 

[Utubereefer]

If you have a property sized sump neither is needed . Happy Reefing

I like big sumps and I can not lie

 

[BryanM]

Took me a while to figure out the right level in my first tanks sump, but once that was set it seemed I didn't need any of the things talked about here.

Am I missing something? If the return nozzles are basically at the top of your water, when the tank drains below that and empties the overflow, how can the tank continue to drain at that point?

My current tank came with a check valve, so I'm not overly worried, I'm just trying to learn.

 

[JayM]

If you have a property sized sump neither is needed . Happy Reefing

^^^^ This. 100%. I don't have the need for a syphon break or check valves. In fact, I completely sealed and waterproofed my stand and it will hold about 4 gallons of water before the floor gets wet. I thought it was overkill because there's no way for my sump to overfill, but I'm glad I did it as I knocked my ATO line out of place the other day, didn't notice right away and pumped about 2 gallons of water inside the cabinet instead of inside the sump.

 

[edd59]

if your doing maintenance and you nock the lock line below water level and dont notice it, it will drain down to where the return is. i have done it but noticed while tank was runnig, luckely

 

[Ziggy17]

As stated, just keep your return nozzles max 1” below the water surface. It will break a syphon and you will never overflow. The deeper the return nozzles, the more water can syphon back. Most sumps can handle a couple extra gallons from the syphon.
And now that you’re paying attention to little nuances like this, be mindful of your ATO. It’s a good practice to ensure your total possible ATO volume is less than what your sump can handle if the ATO accidentally stays on and empties the reservoir, and shortly after the power goes out and the sump fills. If you shut off your return and when all is settled , you have about 6-7 gallons of available volume in your sump before it spills over, don’t use a 10g ATO reservoir, use a 5g. An ounce of prevention equals a dry floor…..

 

[LagunaGlide]

Apologies I've not been around to reply.

My return line nozzles were below the weir level when this happened. So, I should have expected it. The system wasn't even full yet, I turned the return pump off because it was sucking air and had moved all the water out of the sump into the tank, and wasn't draining fast enough. I just shut it off and walked away to continue filling it. Then I heard a noise. By the time I realized what was happening the water level in the tank was below the overflow box. It was all being sucked back through the pump side. I had to close the valves to stop it.

The sump came with the tank from Planet Aquariums. Sure, I could get a bigger sump, I suppose, but I can make this one work.

I will likely get a check valve, and may still drill the holes too.