Repeated Tank Overflows

[nicksgirl]

Okay, I'm ready to admit something is wrong with the design of my system.... I've had THREE overflows in the last two weeks and I can't figure out why. Each time, everything is running along fine until suddenly (for what appears to be no reason at all) one of the tanks begins to fill faster than it is draining... This has happened on both tanks.

I've had the system up only for a couple of months.

I use CPR CS90 "Continuous Siphon" Overflow boxes. They rely on air pumps (to maintain a siphon or to restart the siphon after a drain down). After the first flood, I found an air hose clogged. After the second overflow, (on the other tank) there was nothing found to be wrong with the pump.

Ditto the third flood which occured on the first tank again..

There is a picture of the system in "My Gallery"... Note the return pump is connected via flixible hose that drapes over the edge of the sump tank. Could this pressure be be the cause of my problem?

I have turned off the return pump until I get this resolved. I have powerheads running in each tank but I don't know how long the livestock will be okay like that..

Anyone have any ideas what might be causing this?

[Ziggy953]

Ok...form the pic that I was just looking at I'm not sure of the direction of flow but it looks like you have 2 tanks going into 1 sump is that correct? The return line is too long and I would cut some off so that it doesn't go down and then back up...that is reducing your flow.

It also looks like you have 2 drain lines coming from the "right" tank and going into the sump and into the left tank. Where are they coming out of? The overflow or the tank? Can you get a pic of them and where they are connected? I'm going to say that they are not "droping" enough the horizontal run is creating a problem. I'm guessing that your flood came from the right tank and not the sump.

If you can get me a pic of the back where the plumbing is attached I can better answer what is going on. I think you are going to have to redo your plumbing. The water needs to fall straight down, at least a to the bottom of the tank before you turn the plumbing in a new direction.

[melosu58]

Moved to General Hardware and equipment discussion.

[nicksgirl]

[quote="Ziggy953"]it looks like you have 2 tanks going into 1 sump is that correct?{/quote]
Yes

Originally Posted by Ziggy953

It also looks like you have 2 drain lines coming from the "right" tank and going into the sump and into the left tank. Where are they coming out of? The overflow or the tank?

Each tank has an overflow box and each overflow box drains into the sump via 1" pvc pipe. The drop on those lines is below the bottom of the tank where I have used 45 degree elbows to maintain the downward angle of the the drains.

What you see on the wall is the manifold that carries water from the sump and divides it into three lines. One to supply each tank and the third to act as a spillway or emergency drain back into the sump.

Originally Posted by Ziggy953

I'm guessing that your flood came from the right tank and not the sump.

Right. The sump has not overflowed but both tank have overflowed from the top on different occassions.

What is odd (to me) is that I have been running the tanks successfully for weeks at a time and then something causes something to change. Something changes that make the tanks fill faster than they drain...

I think you're right - I'm looking at a total redo on the plumbing... Meanwhile until I can get that done, I'm planning 50% water changes every other day. Do you think that will keep my fish and coral alive?

[Ziggy953]

I think your problem is coming from the manifold that you have setup. Now that I understand what is going on there I think I can at least point you in the right direction. In order for what you have set up to work out you will have to have exactly the same amount of water going into each of the 2 tanks, that is virtually impossible. One day the right tank will have more or less water in it then the left and then it will switch or overflow. Is that right?

What you need is a circular system. What I mean is that the only place that water level changes is where your return pump is. I have a dual overflow and a triple sump setup but the difference is, is that ALL of my tanks empty into one return sump. The water is pumped into 1 tank and then is split from the overflow into the 2 other tanks. which then flow back into the retun tank. Thus a circular system. What you are trying to do is very difficult to make work because you are using one pump and one sump. The pump will push more water through one side and the switch to the other. It all depends on the amount of resistance on one side of the return line vs the other. Does that make sense?




I think that would be a bit much. What is the reason behind the PWCs? Can you just have one tank running for now until you get your plumbing taken care of?

[nicksgirl]

The pump is too big to run only one tank (without also using the spillway line). But when the last flood happened - that is how I had it running so I don't want to try that again. I understand your instructions (I think)....

I can relate your description to an electric circuit... Your tanks are in a serial circuit... mine are in parallel....

Nick's idea was to put 2 smaller pumps in the (same) sump and plumb each to it's respective tank directly while continuing to drain each tank to the same sump. That would solve the current problem but for some reason it makes me nervous. Do you think it would work?

[Ziggy953]

Actually after thinking about it that is exactly what you need to do. That way if one of the pumps fails the tank that it is on will stop filling up but the other tank will continue to run no problem. 2 pumps one for each tank and you should be fine....what kind of pump are you using now if it is too big??????

[nicksgirl]

I think it is a Mag1800 or 1200... (It was a hand-me-down so I'm not sure) The overflow boxes are rated at half the total power of the pump, I know that..

What I was worried about with this idea is that if I do have the same problem with one of the overflow boxes... (It stops draining and the tank overflows...) What will cause the water to stop going on the floor? It won't stop until the sump runs dry, right? (Which was true anyway, I guess) - but it seems to me there is a danger of draining both tanks ... am I wrong about that?

[mulron]

I'm gonna come outa "lurk" status to put my 2 cents in.

I have run those CPR's for a few years now. I have had this happen a few times. Let me give you some pointers to the CPRs in general.

• *Check that the nipple on the top is still glued in place. If it is not then you will lose suction.
  *I got rid of my air pump and hooked it up to a PH in my tank - worked better for me. IMHO those air pumps don't work as well as a good PH.
  *Keep the hose short to the air pump/PH - helps keep it working properly.
  *If you are pushing the max the overflow can handle it may lose its suction because it pulls in more air with the increased water flow (dial down the return)

The best advice I have to give are these:

A Switch
http://www.marinedepot.com/md_viewIt...product=UL1111
My tanks have egg crate on the top of them so I attached it thru that. This will guarantee the tanks not spilling over. Will not solve the whole problem but it will safe guard your corals and home.

Second

Also have the CPR tilt up a little towards the nipple side. This will help with the air bubble removal. Not much but a few turns of the screw on the nipple side will do wonders.


As far as the plumbing part- It looks like you have a plan already so I'll stop here. If you still want to run everything from 1 pump. Its posible.

[Ziggy953]

Mulron made some good points...I've never been a fan of the airpum method on an overflow....I like the idea of the PH that is how I keep air out of one of mine. As far as the Mag 18 or Mag 12 they still loose power the higher and farther you push the water and from the pic it looks like it is doing a lot of work. Since I'm not familiar with your overflow I will stop here. I use U-tubes in my overflows....

[nicksgirl]

Mulron - The link on your post took me to Marine Depot (love that site) but the product displayed wa a light fixture that I was considering purchasing... I'm sure this is because MD leaves cookies on my computer to keep me logged in - but tell me more about the item so I can find it. I was actually imagining a switch would be perfect.. I was going to invent it myself!

I will also make the changes and checks you suggested on the CPR... Not sure how to hook up the suction nipple to the powerhead though.

You guys are great! Thanks for your help!!

EDIT:... I found the switch! Thanks!!

[mulron]

Sorry about the link - thought I had the switch in my copy buffer.

To connect the CPR to a PH use the venturi hole on the PH. So instead of the tube going to air pump - attach it to the venturi hole by the directional output flow.

In plain English - right by where the water comes out of a PH you should see a hole (might be capped) but you can attach the hose there.





I use these PHs - if you look right by the "fan"/ output of the PH you will see the place where you need to attach it.

Hope I made myself clear -if not just holler. I'll try and explain it another way.

EDIT: if you need to buy a new PH or are concidering replacing the pumps with PHs get something around 200-250 GPH. Should work wonders.

[nicksgirl]

Thanks mulron!
I have maxi-jet powerheads but if I can't find the little hole... I'll just get the one you have pictured here.

The manifold is already in pieces on the floor (RIP) and I have new pumps on the way! Wish me luck and thanks again! I think we've got it figured out...

[Ziggy953]

Hey....keep us informed! I hope all works out!!!!

[mulron]

I hope all works out for ya!
holler if ya need something.