Help :( Overflow on custom tank mounted too high

[dopey]

Had a custom tank ordered and the store was kind enough to drill the tank and mount my overflow on it.

Have just filled her up enough to test full flow -- overflow going with return pump.

The water line is faarrr too high.

Looking at the instructions I think it was an honest mistake. The sheet said for a rimless tank to use the template where the top of the overblow box be 1/4" or more *below* the rim of the tank. My overflow is basically flush or a mm above the rim of the tank.

Here is the overflow box itself: (water level is low from draining down into sump/power off) -- The return line is lower than the slits so it drains down to there.

It's a modular marine 800gph overflow.

Aside from getting a new tank/backpanel made.. what options do I have?

The first idea that came to mind was taking a dremel and extending those slits in the overflow farther down. The actual drilled holes are lower than the teeth. If I extend those teeth farther down, that will lower the water level right?

Any other suggestions?


After 3 days of filling the tank after work, bit disappointing to say the least

Bonus question: One of the uniseals has a slight drip on the overflow. I thought these were just apply silicon grease/slide in the pvc pipe? any suggestions?


Some more photos of the build in general on my build thread: https://www.reef2reef.com/threads/new-custom-tank-230l.631917/ .. figured better to make a separate post since my build thread is mainly me talking to myself

 

[bdesign]

.. figured better to make a separate post since my build thread is mainly me talking to myself

HAHA
I feel you on feeling like you're talking to yourself.

I wish I had some insight for your predicament, but I'm less than unknowledgeable.
Your proposal of extending the slits makes sense to me, but... again... I'm... well, you know already.

 

[Topreefer92]

So for the overflow, yes you can dremel that overflow down and it will lower the water level. For the uniseal is it like a actual uniseal or a slip fitting that PVC fits into? If it is pvc to pvc use PVC glue and that should fit it perfectly. If it is abs bulkhead still plastic do not use the cleaner stuff before gluing (usually purple). That stuff will degrade the abs plastic in the bulkhead over time.

 

[dopey]

Thanks @Topreefer92 ! I can't think of another solution than to dremel.. but then again lots folks know lots more than me in this hobby

As for the seal. It's a uni-seal per the site:
"- Three 1/2" or 3/4" uni-seal drains (message us if you want the 3/4" uniseals)"


To be honest I was a bit shocked when I got it. Was expecting typical bulk heads and i'd glue in PVC But it seems uni-seals you apply silicone grease and slide in the pipe.

Practically that means it's soft rubber -> PVC.. Not sure pvc glue be a good idea

This particular seal has allot more 'movement' than the others did. The others are quite snug but this one goes up/down vertically, perhaps it's been damaged?

 

[WVNed]

I dont run rimless tanks but that is about how high my water is. You just don't see it.

How much do you want to lower the water level?

How high is the water level in the front and rear boxes of the overflow.

The level in the main tank is determined by how fast the water is pumped into it. How fast the water can get through the overflow teeth and how fast it drains back down.
If you want more flow than will pass the teeth you make them bigger until it will.

Do you have an adjustable flow return pump. Turn it down a bit.


I suppose I would dry the uni-seals put silicone sealer on the pipe and shove them back into position.
I never use uni-seals except for emergency drains that are dry until something goes wrong like in my water storage containers.

 

[zalick]

As to the Dremel option, the answer is maybe.

I think we need more information. I assume this is a beananimal type over flow with three drains? These drains will dictate the height of the water as well.

If the drains are below the slits, then yes, dremeling should work just fine.

You want to make sure the water still falls so you are getting surface skimming action.

 

[dopey]

Like to lower it maybe 2-3x lower than it is now. Maybe it's fine but my today we keep our tiny tank a good 1"-1.5" lower than the top.. So seeing this behemoth sitting there with 150L of water and a pump going and splashing from the overflow(Not plumbed it all the way into sump yet).. Well it was a bit too much for either of us to go to sleep at night with confidence

As for tank water level -- I had ready many times that my secondary pipe in my overflow 'determines water level', but I just don't understand that It would only determine the water level if the teeth(inlets into the box) are *lower* than that pipe. In this case, the inlet teeth are the highest point in the tank and overflow box. Until water hits the teeth nothing goes into the overflow box... resulting inthese teeth setting water level?

I never came close to a full syphon(adding to the noise/stress of my partner). My thinking is the pump wasn't pumping fast enough to keep up with the drain rate. I'll take a video of the tank going and share it.

 

[zalick]

You are close to fully grasping how the overflow works. WVNed is spot on. All 3 factors he mentions can affect the level.

You can adjust the depth of water in the external box by adjusting the height of the backup drain. The only requirement is that the backup drain is higher than the opening of the full siphon.

The backup drain should be below the bottom f the slits so you are skimming the surface.

 

[dopey]

Here's a video of it running:

The plan is a beananime with 3 pipes. I haven't added any tops to them for silencing yet, nor plumbed the rest into the sump yet. Goal was a leak test before continuning with plumbing work

The pipe nearest the camera you cannot see, but it's very close to the bottom of the overflow box, and meant to be the 'primary'. The center pipe is emergency and the far pipe is the secondary pipe.

All pipes are below the teeth water level in the tank, so I don't see how to decrease water level without lowering the teeth?

How 'safe' is it to use a dremel on acrylic? Am I just as likely to crack/run the box?

 

[X-37B]

I would order a new overflow box and explain that you need the slots lower. I dont think the dremel would look good imo. With the uniseal I just get the pipe wet and slide it through. I would not use any type of grease. I have used this method with hydro setups for years with no leaks.

 

[zalick]

It's easy to crack acrylic with a Dremel. I've done it many times....

I agree with you on the water level. Too high for my comfort bon a rimless.

 

[dopey]

I would order a new overflow box and explain that you need the slots lower. I dont think the dremel would look good imo. With the uniseal I just get the pipe wet and slide it through. I would not use any type of grease. I have used this method with hydro setups for years with no leaks.

That is a good idea long term. The challenge being in Europe, is its a good 6-8weeks to order a new overflow I will reach out to them and see if they are open to making the slits lower.

It also took 3-4 months ordering the custom tank, so getting a new tank/back panel done.

The joys of when things go wrong

 

[dopey]

You are close to fully grasping how the overflow works. WVNed is spot on. All 3 factors he mentions can affect the level.

You can adjust the depth of water in the external box by adjusting the height of the backup drain. The only requirement is that the backup drain is higher than the opening of the full siphon.

The backup drain should be below the bottom f the slits so you are skimming the surface.

But since these slits are so high, the drains at this point have no affect on water level right?

 

[Jon Fishman]

I would rock it at the higher water level. Looks better

 

[zalick]

Are the elbows already on the primary and backup?

I think you will need/ want to have it all setup before adjusting. Can you post pics of the drain elbows?

 

[zalick]

But since these slits are so high, the drains at this point have no affect on water level right?

As setup, correct.

 

[dopey]

Are the elbows already on the primary and backup?

I think you will need/ want to have it all setup before adjusting. Can you post pics of the drain elbows?

The pipes are running down vertically from the overflow, then a 45 degree elbo through the back of the stand and over the sump. I will add another 45 on the primary/secondary to bring it under water level and keep the emergency above the water level.

I haven't put any elbows within the overflow box itself yet.. honestly had hoped I wouldn't need to depending on the sound The space to work in the box is quite limited and I also haven't been able to find the 'u' shaped elbow in 20mm. Local fish store is basically only place with 20mm pipes.. big box stores only have larger pieces.


As for modifying the acrylic, it seems dremel is a bad idea (Was just first thought) after some googling. Likely to clog/heat/break. I am probably better off with a small hacksaw/blade and doing them by hand?

 

[Radman73]

I would rock it at the higher water level. Looks better

+1.

My 60 cube water level wasn't too much lower than that.

 

[zalick]

I haven't put any elbows within the overflow box itself yet.. honestly had hoped I wouldn't need to depending on the sound

If you want a dead silent beananimal, I think you will need elbows on at least the main. I've never tried without. I think you'll run higher risk of pulling air.

As for modifying the acrylic, it seems dremel is a bad idea (Was just first thought) after some googling. Likely to clog/heat/break. I am probably better off with a small hacksaw/blade and doing them by hand?

Yes. I have successfully dremeled teeth in acrylic but it's tough to not screw up.

 

[zalick]

+1.

My 60 cube water level wasn't too much lower than that.

His height will limit any wave action he might want. But it does look nice!