1/2" drain herbie

[mlivvy]

I've got a 50g SCA cube with a 1" and 1/2" hole in the overflow. I set it up with a durso but, no matter what i've done I can't quiet it down. My previous tank had a herbie overflow and i'd like to go back to that. I found someone with the same tank who went with the 1/2" herbie but, he hasn't updated in a few years.

I wonder if a 1/2" emergency drain will be ok. I was thinking of using strainers on both the 1" and 1/2" pipes to prevent clogging or snails. Also, will using 1/2" to 1" adapters make a difference? Thanks for the help!

 

[sbash]

Are there valves on the overflow pipes already?

I would try the 1/2" as the full siphon first and see if it works. I would be more comfortable with a larger emergency/overflow pipe than a smaller one.

Definitely use strainers, those snail shells will find a way!

 

[mlivvy]

Are there valves on the overflow pipes already?

I would try the 1/2" as the full siphon first and see if it works. I would be more comfortable with a larger emergency/overflow pipe than a smaller one.

Definitely use strainers, those snail shells will find a way!

I have a valve on the 1" line now. I think i'll try the 1/2" as the drain. It's handling the return pump fine with lots of flow so I don't see it being a problem.

 

[doughboy]

I have SCA 50 and use 1/2" as drain and the 1" for emergency. The 1/2" can handle plenty of flow if you keep it straight (no elbows or 45 deg) down to your sump and no strainer. Strainer will cut your flow capacity to half. Set the pipe height inside the overflow around 1/3 to 1/2 the height of the overflow box (max flow if there is no 1/2" pipe inside the overflow). I have a valve on both drains with emergency fully open and 1/2" closed slightly. I could leave it wide open also I suppose, as I control the flow via DC return pump controller, way better and easier than messing around with valve.

 

[mlivvy]

@doughboy Just what I needed to hear thanks. Do you have just a straight 1/2" and 1" pipe in the overflow? How did you plumb the returns?

 

[doughboy]

yes, both 1/2 and 1" pipes just come straight down to my sump, no elbows or any bends.
I did over the top return, similar to the link you gave.

I experimented with all known tricks with durso and eventually gave up and used herbie.
I had evaluated using 1/2 vs 1, and since 1/2" was able to handle the flow I need, I went with 1/2.
You can actually get an even higher flow if you can find 1/2" pvc that is thin wall. My local homedepot has 1" pvc thin wall, but not the 1/2" pvc.

 

[mlivvy]

I found a thin wall 1/2” pipe. Is the height good enough??

 

[doughboy]

did you find the 1/2" thin wall at big box store?
the 1/2" should be about half the overflow box. it needs a few inches (maybe 3-4) of water above it before it can get full siphon.
The shorter the 1/2" pipe, the higher the max flow you can get out of it. So if 1/2 overflow height does not get you the flow you want, you can shorten it further.

 

[ca1ore]

Other than preventing tank drain down in the even of overflow/weir failure (which almost never happens), there's little other value to having a standpipe for the siphon. I just use a strainer right into the bulkhead.

 

[Jason_J]

How much flow are you trying to push through it? It may be hard to quiet down if you are close to the max of the pipe size.

 

[mlivvy]

did you find the 1/2" thin wall at big box store?
the 1/2" should be about half the overflow box. it needs a few inches (maybe 3-4) of water above it before it can get full siphon.
The shorter the 1/2" pipe, the higher the max flow you can get out of it. So if 1/2 overflow height does not get you the flow you want, you can shorten it further.

I found the thin wall pipe at Lowes but, it wasn't something they sell. It went to I believe a water tank and ended up on the floor in the plumbing section. I asked if they can sell it to me and they did. The problem I see with cutting down the pipe is that i'll get alot of splash noise from the water coming into the box.

How much flow are you trying to push through it? It may be hard to quiet down if you are close to the max of the pipe size.

I think the max on the return pump is 792 gph so i'm looking at about 600 gph.

 

[Jason_J]

That's probably a significant factor. If you turned the return flow down to 200-250gph the drain will likely be much quieter.

 

[doughboy]

I found the thin wall pipe at Lowes but, it wasn't something they sell. It went to I believe a water tank and ended up on the floor in the plumbing section. I asked if they can sell it to me and they did. The problem I see with cutting down the pipe is that i'll get alot of splash noise from the water coming into the box.


I think the max on the return pump is 792 gph so i'm looking at about 600 gph.

The water splash only happens at the start. It always does no matter how high you set the 1/2" pipe. That's what the valve is for, to tune the final water height in the overflow. The 1/2" drain is supposed to be completely submerged with full siphon. If it is too close to the surface, it may not get full siphon and create a whirlpool at the surface.