Marineland Corner Overflow Issue

OneFishTwoFish

Active Member
PREMIUM
Who has a properly dialed-in Marineland Corner Overflow ? I've got a 120 gal, and I'm having issues getting the overflow dialed-in. It's been good for 4 months, but in the past 2 days, my water level kept creeping up to a dangerous point. I made adjustments to get the water level back where I wanted it to be. But, now I have an extremely noisy overflow.

After hours of tinkering, I realized that the "overflow cover" (it's on the tank-side of the overflow wall) had some algae on it which might be restricting flow from tank-side to corner overflow, so I cleaned that. It made small improvement.

At this point, I can't set a reasonable water level in the tank without having a very noisy overflow. If I increase the water level so that the overflow gets quiet, the water level continues to rise, very slowly. I stop the rising water level before anything spills out of the tank, and we begin adjusting everything again.

I have ball valves in the tank-to-sump and return-pump-to-tank lines, so that's where I'm making adjustments. My sump is in the basement, so water travels a fair distance (approx. 15 feet). I have an Iwaki return pump -- plenty of pressure. In fact, it's dialed down to 75% through the return-pump-to-tank ball valve.

Where do you have your water level at with this type of overflow ? I thought the 'ideal level' would be so that the water flows through the slots in the weir that's at the top of the overflow. I think that the water level is too high when water begins to flow over the top of the weir.

Pictures of where I am now:

Front View - This is what I consider to be the 'ideal' water level:
IMG_2794_zps41d45e66.jpg


Top View:
IMG_2797_zps42f68005.jpg


Side View - not enough water in the corner, therefore it's very noisy:
IMG_2796_zpse01b9d2c.jpg


Any thoughts ?

---Frank
 

sirrealism

Well-Known Member
That looks the same as mine. I was worried about it at the start but it has worked great. i am using a 1500g per hour blueline pump with about 4' head. Can you post a pic of when its running high? Could you have gotten a snail in the return?
 

sirrealism

Well-Known Member
I will look close at mine tonight and take a pic and post it here tomorrow so you can see my water levels
 

OneFishTwoFish

Active Member
PREMIUM
Thanks for the replies Sirrealism. I thought there might be something stuck in the overflow pipe so I removed the top elbow and looked in. I can see down to the ball valve that's below the tank - no obstructions. I might run a fiberglass snake through there and down to the sump, just to be sure. I'm plumbed with 1" SpaFlex from that ball valve all the way to the sump.

I did some web searching and found two ideas -- (a) put a small cable-tie into the anti-siphon hole that's in the return line to quiet it down (b) cover the anti-siphon hole with something that still would allow air into it when your return pump stops. I tried the cable-tie -- still very noisy. Then I tied a piece of 'glass scrubby pad' over the hole and that greatly reduced turbulence in the corner area.

Here's what I did (blue fuzzy pad and black cable-tie):
IMG_2800_zps47a6a080.jpg


I tested the above-noted modification several times (return pump on / off) and the siphon break still works fine. Even if it didn't, and water continued to flow to my sump until the return nozzles were 'out of the water', I'd still be fine. My sump is built in a standard 75 gallon tank and my normal water level in there is only 9 inches. So there's plenty of 'expansion space'.



After that experiment, I was able to get my water level stabilized in a position that I was comfortable with. I have the water level just a bit higher than the black frame that tops the tank (so from outside the tank you won't see a water line):
IMG_2802_zpseef28704.jpg


At the center support, the water is approximately 3/8 inch below the plastic. When the water was rising, it touched the center support. I don't think that's good as it interferes with circulation and causes a bit of splashing through my mesh cover.
IMG_2798_zps50287a38.jpg


My water level has been stable for 2+ hours now and the overflow is very quiet. I would not call it silent -- you can hear some running water. But it's a pleasant sound. Nothing like a constant toilet flush !

I'd like to see a picture of your water level, when you get a chance.

Thanks
---Frank

IMG_2802_zpseef28704.jpg
 

sirrealism

Well-Known Member
Good Job Frank. I bought my tank used and running. its a 93 cube but has the same set up for the overflow. i will get you those pics tonight and post them tomorrow. When I was reading this I was going to suggest one of those little air filters for a skimmer air lin but seems you have the same idea so glad it worked
 

may2024

Member
I had a very similar problem I ended up increasing the size of my vent tube got rid of flushing sound and tank drains at a constant rate now.

My phone.
 

OneFishTwoFish

Active Member
PREMIUM
Took me a few days to figure this out . . . My vent tube was clogged ! It certainly looked clear, but it had some salt deposits deep inside and no air could pass through it. After cleaning the vent tube, I'm back to having a very stable water level. I've added the vent tube to my list of regular maintenance tasks.
 

sirrealism

Well-Known Member
Good deal. I guess i need to find mine and check it LOL. As I said I bought mine as a running system and have had no issues with it. I did take pics but then could not find this thread to post them

Sorry for the crappy cell pics but
Got tanks !!!!!!!!
 

sirrealism

Well-Known Member
And no I am not single but if i dont get this 300g 8' tank built and running and get rid of a bunch of these tanks i will be single. Every time my wife walks into this room she shakes her head and walks out
 

OneFishTwoFish

Active Member
PREMIUM
Sirrealism, that's quite the Fish Room ! Can't wait to see your new 300g come to life.
The vent tube that I unclogged on my tank is located on the top of the pipe that drains to the sump. It's a hard plastic tube, about 1.5 inches tall. You can see it in some of my pictures, above. It seems that your vent tube is missing. In your first picture above, the elbow in the foreground has a hole on top of it. The vent tube goes in that hole. If the water in the overflow corner covers the hole (without a vent tube), a full siphon will probably occur, and that syphon will break when the hole is no longer covered. Stick a piece of airline tubing in there and have it extend about 1.5 inches above the elbow. That should eliminate the syphon / syphon-break cycle and make the overflow a bit quieter. Now that I've cleaned out my vent tube, my water level is very stable and the overflow is near silent.
 

sirrealism

Well-Known Member
Thanks Onefish. I saw it in the pic when I posted it. Mine if very quite already but I will put a tube in it. Some of my other tanks are not so quite but its not girgling just water running and splashing which i find kind of relaxing. The fish room was a big mess when I took the pic. I have not had time to get it cleaned up since we started painting the rest of the house. That was the deal. Get the honey do things done around the house then I can put up the new tank. When the new tank is done then I will take down 4 of the tanks I have running. Well 3!!! maybe only 2 LOL
 
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