Plumbing...suggestions? Added a drawing...

[Myka]

I'm good at putting it together, but my plumbing ideas usually suck!!!

I'm going to use this style of external overflow:


I have a 3/4" return, running a pump that will deliver about 700 gph. According to a plumbing calculator the minimum overflow should be 1.09". So I think I'm really pushing it to just use a single 1" overflow. So, should I put two 1" or a single 1 1/2"? I don't want anything in the middle of the back of the tank up high (esthetics), but I'm considering putting my return in the middle of the back down low say 3" off the bottom, then have two 1" overflows in each of the upper back corners. If I use two 1" overflows (which I'm leaning towards), should I use a single external overflow for the two across the whole back of the tank, or should each bulkhead have it's own external overflow?

Good idea? Bad? I dunno...? Suggestions?

I don't see many people with check valves on their returns, but I think I will. Is there any reason not to?

Also, can you guys post some pics of how you've incorporated a waterchange valve or some such into your plumbing?

[Parker]

but I'm considering putting my return in the middle of the back down low say 3" off the bottom

The only problem I see is, If the power goes down you’re going to siphon all the way down to the level of your return. A closed loop return down low would be fine, but not a sump return even with a check valve, they have a tendency to fail, it doesn't take much to keep them from closing all the way. This is assuming that your return is through the tank not over the top.

[Myka]

Ah...good call.

[mark]

Rather than a bulkhead to feed the external overflow do a single large notch the width of the box or a series of smaller one (see picture in this thread).

And make a Herbie, drilling the external box for two holes. In your picture the air being pulled into the drain must be making an awful sucking sound.

[Myka]

Originally Posted by mark

Rather than a bulkhead to feed the external overflow do a single large notch the width of the box or a series of smaller one (see picture in this thread).

I don't know how to do that to glass, and I don't want to risk breaking the pane. what's wrong with using a bulkhead?

Originally Posted by mark

And make a Herbie, drilling the external box for two holes. In your picture the air being pulled into the drain must be making an awful sucking sound.

Yes, now that I think of it, I've seen a couple plumbed kinda like that, and they were very noisey. I've heard lots about Herbies, and I have no clue what they are. I'm going to go researching.

[fkshiu]

Originally Posted by Myka

Yes, now that I think of it, I've seen a couple plumbed kinda like that, and they were very noisey. I've heard lots about Herbies, and I have no clue what they are. I'm going to go researching.

Take any overflow box - internal or external, doesn't matter - and drill two holes in the bottom (holes will be in the bottom of the tank for an internal box). Put an ordinary standpipe in one hole. Leave the other hole as is. Put a gate valve under the no standpipe hole and adjust it so the water level in the overflow box is just seeping down the standpipe. Voila . . . dead silent overflow a.k.a. a Herbie.