Aquarium Plumbing for Two Overflows Questions

[Reef-junky]

So for that idea I would have both overflows functioning in that way with the 1" being the emergency and main is the 3/4" then use 1 pipe going over and up the back of the tank into the display?

Yea

 

[mjlash22]

I was just simply expressing my personal opinion on the matter and what I've seen done by other individuals in the hobby. I was not expressing it should be followed. I can say that one of the largest tank manufactures sets up their plumbing 32mm main and 25mm emergency. Wrong or right, it's what they decided to do and it works. I have had this set up for years with no issues.

There are many fail safes in this hobby, especially nowadays with all the technology. One idea would be a float switch which would turn off your return pump in the ocurrence that your water level rises to the extent a flood could happen. But even then, that could fail! What happens if both drains clog? What if the water leaving the DT floods the sump? Many things COULD happen.

The ideal fail safe would be to calculate water height in the tank from the top of the water line to the top of the overflow box teeth and water volume in the sump and ensure that no matter what situation may happen, you won't have a flood due to a clogged drain.

 

[Reef-junky]

Is it safer to have a lager emergency drain or a smaller one? So now you want to rely on a float switch which are know for failure as a solution to improperly sizing the emergency drain?

 

[Smo]

Not the best at using a measuring tape but I believe they are 3/16th inch for each hole with 23 total on the top.

Using a rough weir calculation your overflow could handle approx 250 gph with 1/2” of flow thru the slots and 490 gph with 0.8” of water depth flowing over the slots. This does not account for the additional slots you have near the bottom which increase total flow slightly.

 

[Reef-junky]

If you completely plug the main drain and you are running it close to capacity you think a smaller pipe is going to handle that? What would be the advantage to running a smaller emergency drain? Even if the pipe was able to handle the same capacity would it not be better to have the emergency drain slightly over sized so you know full well that it can more then handle any blockage that could and will happen? We also increase the chance of the second pipe plugging by having it smaller.

 

[mjlash22]

Take the drain sizes out of the picture for a moment. If you want to completely avoid the potential for a flood, the sump has to be designed in relation to the tank it is being used for. If you have correctly laid out and designed the sump and overflow of the DT, you avoid any and all chance of a flood no matter what situation happens (clogged drain, dead pump, etc.) Short of something cracking in either.

In the case of a drain(s) clogging, no matter the size, your return pump chamber should be designed in a way that it is empty before your DT would overflow/flood. You can do this by properly designed/placed baffles in the sump.

In the case of a dead return pump, your sump should be tall enough to allow for an increase in volume/water height from the difference of the top of the tank's water line in the DT to the overflow box teeth.

If you do not design/calculate the sump and tank overflow correctly, you still will have a high probability of flooding one or the other no matter if a drain clogs or a pump dies.

 

[Reef-junky]

It doesn’t make any sense to have an emergency drain smaller then the main drain. Like I said it’s just a bad design. All your doing is increasing the risk of a flood.

 

[Zxandak]

If I do a Herbie on both overflows with the 3/4'' main and 1'' emergency would I even be able to get enough flow for the tank or am I better off fixing this up and selling it and buying a tank cut for a ghost overflow like reef savy or similar for a BeanAnimal method?

 

[Smo]

What flow rate are you attempting to achieve? With both overflows you should be able to see on the order of 1,000 gph.

 

[LagunaGlide]

I just plumbed mine Herbie style to have the main drain in one overflow with the emergency drain in the other overflow. Returns in both. I looked into this a god bit, and found there are people who have had success this way. My setup will have water in it soon at which point I will report back as to how it works out for me.

 

[Zxandak]

What flow rate are you attempting to achieve? With both overflows you should be able to see on the order of 1,000 gph.

I just want enough to be able to support any coral or fish needs and possibly doing the Triton method with the sump. What size pump would I be looking at?

 

[Reef-junky]

You only need 3 to 5x the turn over of your DT. As far as the pump you need to take into account head loss. If you use PVC then you need to take into account friction from pipe size and fittings. As you can see from the chart if you run a single pipe into a T and split it you create more flow loss from your pump then using a 90• fitting. If you going to T off the return run it up and down not one pipe and then splitting to the sides. You may not get very good flow on one side by doing this a Y might be the best option.

 

[Reef-junky]

I would flow the general guidelines of this:
It’s of course not the only way to do things but it’s solid advice and will keep you from having a lot of potential problems.

http://gmacreef.com/herbie-overflow-reef-tank-plumbing-method-basics/

 

[Zxandak]

You only need 3 to 5x the turn over of your DT. As far as the pump you need to take into account head loss. If you use PVC then you need to take into account friction from pipe size and fittings. As you can see from the chart if you run a single pipe into a T and split it you create more flow loss from your pump then using a 90• fitting. If you going to T off the return run it up and down not one pipe and then splitting to the sides. You may not get very good flow on one side by doing this a Y might be the best option.

So I was looking at doing the 1'' as the emergency and the 3/4'' as the main and then for the return would a Y be better and have it direct off to both sides of the aquarium for flow on both sides or would it be better to just have 1 pipe, I can do any of it, I havn't bought anything yet just trying to plan it out first. Tanks I've had in the past I rushed into it and didn't plan out everything as I should have.

 

[Zxandak]

As far as I understand it I am basically doing this with both overflows?

 

[Smo]

As far as I understand it I am basically doing this with both overflows?

Give it a try. Experiment. That’s half the fun. But use gate valves—not ball valves.

 

[scott11106]

i believe with the triton method you want at least 10x flow..

 

[LagunaGlide]

The best route would be to herbie both sides with the small holes being the main drains, and the larger being the emergency. Just know that you will have to run your return over the top. I chose not to go this route only because I wanted the tank against the wall.

 

[Reef-junky]

Give it a try. Experiment. That’s half the fun. But use gate valves—not ball valves.

+1

 

[Reef-junky]

So I was looking at doing the 1'' as the emergency and the 3/4'' as the main and then for the return would a Y be better and have it direct off to both sides of the aquarium for flow on both sides or would it be better to just have 1 pipe, I can do any of it, I havn't bought anything yet just trying to plan it out first. Tanks I've had in the past I rushed into it and didn't plan out everything as I should have.

You probably don’t need a dual return pipe. The return is not there to add flow to the tank but to run the sump.

As far as the overflows you could have one by the skimmer and the other by the refugium with the return in the middle of the sump. This is of course one of many possible set ups.