**Overflow Issue** HELP!!

[GuyeWinfield]

Hey everyone!
First off, thank you for taking the time to read my thread. I could really use some help. I am relatively new to the hobby of saltwater reef tanks. I just recently bought a 72 gallon bow front tank with a 30 gallon refugium. It has plumbing already attached and an overflow box with 3 drains. Primary, secondary, and emergency drain. It also has 2 output lines. I will attach pictures so you can see the entire setup.

Okay, so on to my overflow issue...

My first attempt at filling the tank wasnt such an easy process, as the drains required some fine tuning to get the flow perfect. Nevertheless, some trial and error, I was able to get it flowing perfectly. I didnt feel comfortable leaving the tank running over night, so I decided to shut off the pump. The overflow box was empty, so as the water settled, I thought I was safe. That was my first mistake. I didnt think to close the ball valve for the output line and the output hoses were submerged underwater. So yes it caused a syphon and drained water, I woke up to the tank water level about 3 inches below where I left it and the refugium was filled to the brim and had overflowed. I drained out some water and decided to give it another shot a few days later.

My second attempt was last night. I filled the tank up like before and got it up and running with no issues. It ran for hours with no problem. Due to my incident a few days earlier, I didnt feel comfortable leaving it running overnight. So this time I shut off the pump, closed the ball valve, and even pulled my output lines out of the water. The overflow box was dry again, so there should be no way for water to get through the line this time, right? Wrong again. Woke up this morning to the tank level down 3 inches again and the refugium filled to the brim.

I am seriously at a loss for words. The only other thing I can possible think of is that there may be a small unnoticable leak into my overflow box, which overnight is filling up and going down my drain pipes. I really want to get this water thing down, because if I ever have a power outage, I dont want to have a mess in my house.

If anyone has ever experienced such issues or has some suggestions, I would really appreciate it. This thing is getting frustrating, as I dont know where the water could be coming from. If you have any questions, dont hestitate to ask.

Thanks!
Guye!

Some pictures are attached...

 

[spoonman]

You have 2 drains that turn down into the water, they will syphon until the water is below them. Other thing is that if the bulkhead for your returns is under water that could create a syphon and drain until the water level is below it. Just spitballing here.

EDIT: I just noticed what looks like a check valve in the return lines, so it shouldnt be draining there, unless it is stuck open. About the only thing you can do it shut it down and watch it for awhile and see where the water is coming from. Sorry I couldnt be more help.

 

[GuyeWinfield]

Yea my first overflow disaster, I figured it was from the bulkheads syphoning back to the refugium because they were under water and I hadnt shut off the valve on the return lines. So when I attempted it the second time, I made sure that that was all taken care of, but I was wrong again.

Now what you are saying about my downward facing drains, kind of goes with my second to last paragraph about the overflow box possibly having a small unnoticable leak. That is the only other way I can figure out water is getting down there. Water has to be getting in the overflow box slowly and filling up the box and then going down the drains.

I am going to drain it all down this weekend and try to silicone the overflow box and see if that is the culprit.

Thanks for the help!

 

[Ingy]

I would take a second look at the return if the tank is draining down to that level. The check cables can easily plug up with gunk and cause a very slow leak.
You could add a syphon break in the return by drilling a small hole in the return line just below the normal tank level. If it try's to syphon back into the tank the hole will let air in, breaking the syphon.

 

[Ingy]

Why does apple think valves are spelled cables?
Anyhoo, check valves not check cables

 

[GuyeWinfield]

Thanks Ingy!

I am not sure if it is draining to the level of the returns or the level of the drains, as they are at the same level. I did notice this morning that the overflow box had more water in it than when I went to bed. When I shut off the pump, the water clearly dropped below the the downpipes and no other water was being drained down. This morning the water was touching the downpipes, making me thing the overflow box has a leak and allowing water to slowly get in there.

I am going to drain it down some this weekend and silicone everything up and then try again. I may also go ahead and drill that hole while I am at it.

I will keep ya posted on the outchome.
Thanks for the help!

 

[manbeast]

I would take a second look at the return if the tank is draining down to that level. The check cables can easily plug up with gunk and cause a very slow leak.
You could add a syphon break in the return by drilling a small hole in the return line just below the normal tank level. If it try's to syphon back into the tank the hole will let air in, breaking the syphon.

I agree with this, it was the first problem I had with a sump and it is the easiest an fastest fix, I would try this first, if you want to check if the return lines are back siphoning adjust the lines so the output nozzle is at the surface of the water when the tank is full and running then shut the system down and see how low the water goes if it only goes as low as the return lines that's where your problem is if the water drops below your return lines then I'd start looking at the overflow

 

[GuyeWinfield]

That was my initial thought from my first fill, but last night I pulled the intake nozzles strait up out of the water and got the same result this morning. Plus I had closed the valve on the intake line. You still think with the nozzles out of the water and the valve closed, it would still leak through the intake lines?

I'll take a look at that tonight.
Thanks!

 

[GuyeWinfield]

So I just got home and my overflow box, which was basically empty when I left for work, is now halfway full. It has to be a leak in the overflow. How else would that fill up if the pump is off and the tank water level is halfway up the overflow wall.

 

[Engineer Brian]

I think you are siphoning from your return (the line that pumps water from the sump to main tank). I doubt it is your overflow or drains to the sump. Looking at your plumbing, there is a triangular looking device between the pump and your TEE. Is that a SCWD (Switching Current Water Device) or a check valve? It looks like a SCWD to me but they are usually black. Does water return to your display tank on both sides simultaneously or does it switch back and forth? If it switches you have a SCWD.

You need to have a check valve (only allows water flow in one direction) in your return line. They are about $10 at most aquarium dealers on line.

Also, I don't have any experience with a drain setup like this but looking at your drain plumbing, I think it is correct. I think you want to have one of the lines pointing up (the emergency line). The water will spill over the emergency line and down into the sump if your first two drains are plugged.

Good luck... I've been down this road before... Now I always run check valves, and keep a spare on hand. Let me know how it turns out.

 

[GuyeWinfield]

Water flows out simultaneously, so I don't think I have a SCWD.

Look at this picture. I haven't touched the tank since I shut it off. My return lines have been up and out of the water, above the tank actually. You can also see that the overflow box, which was empty, now has the same water level as in the tank. Wouldn't that mean water is leaking into the overflow box? How else could water get in there?

 

[GuyeWinfield]

***UPDATE***

Just drained the tank hallway and found the culprit. Look at this picture. Not sure if you can see it, but water is leaking out the left corner of the overflow box.

So when I shut off the pump the tank is full and the overflow box is dry. Overnight water is going in through this leak and filling up the overflow box and going down the drains.

 

[Engineer Brian]

Good find... When you fix it make sure you use aquarium safe RTV. Also check out that triangular piece in your return plumbing. I'd have to guess its a check valve since it isn't a SQWD. If it's a check valve you are in good shape, if it isn't I'd highly recommend putting one in.

 

[GuyeWinfield]

Just siliconed every inch of the overflow. Waiting for it to dry and I'll be testing it to see if I solved my leak/overflow problem. Also bought a surge protector/battery backup today. Hopefully both with help me sleep at night and I won't wake up to a flooded living room.

 

[GuyeWinfield]

Used black silicone.

 

[GuyeWinfield]

FYI that triangular piece is a PVC check valve.

I just filled my tank to test it again. Fingers crossed that the silicone sealed up that leak.

 

[GuyeWinfield]

Two days running and no leaks! Problem solved. Thank you everyone for the help!

 

[manbeast]

congratulations and no problem on the help isn't that wh

 

[manbeast]

why most of us are here

 

[GuyeWinfield]

Very true. Just like to show my appreciation.