diy overflow

[soggysandwich]

this thing is great, i wanna build one for more of toping off the tank not filtering reasons. so i just have a few questions.

1. I know the pipe on the outside of the tank with the open top is so a second siphon doesnt start, my question is does it have to be so long?

2. How thick of PVC do i need to use for a 90gph pump, so that the tank doesnt overflow? 1/4in, 1/2in, 3/4in, 1in? i dont want it to be to thick i only have a 20gal.

3. Do the pipes need to be glued together, and if so what kind of glue?

4. Lask question, how long do the pipes inside the tank have to be? or does it not matter?

thanks for all the help and for this great DIY.

 

[Lil_Stinker]

this thing is great, i wanna build one for more of toping off the tank not filtering reasons. so i just have a few questions.

1. I know the pipe on the outside of the tank with the open top is so a second siphon doesnt start, my question is does it have to be so long?

2. How thick of PVC do i need to use for a 90gph pump, so that the tank doesnt overflow? 1/4in, 1/2in, 3/4in, 1in? i dont want it to be to thick i only have a 20gal.

3. Do the pipes need to be glued together, and if so what kind of glue?

4. Lask question, how long do the pipes inside the tank have to be? or does it not matter?

thanks for all the help and for this great DIY.

1. Yes, it must be the highest point. (if not then you will siphon. the water will flow out of this pipe if it is is lower)

2. 90gph is rather slow, 1/2 will likely work but go 3/4 or better so you can increase the flow if needed.

3. The pipes outside the tank MUST be glued if you don't want water on the floor, any (clear) PVC cement safe for potable (drinking) water.

4. Most people keep them long, you need to be sure they are long enough to NOT get air trapped in the top loop. So I say the longer the better (hit the bottom)

Hope this helps

 

[soggysandwich]

thanks for answering all my questions, now i can get this thing made and my mom will stop buging me about my tank water being low. and i know 90gph is slow but my tank it only 20gallon so that still gives me a 4.5x turn over rate, and the main point of this (for me anyway) is not filtration.

 

[soggysandwich]

i changed the design a little will it work?

 

[CHOMPERS]

That works, but if you have large fish that create tidal waves at the surface while feeding, the "waves" can introduce some more air in the overflow. I had it happen once when my perch went crazy.

I missed this post, so sorry for the long delay in this response...I added some check valves to my newest overflows and they are the greatest thing since sliced bread. They don't get used much, but when they do they are the handiest things in the world. They are definitely well worth the money and trouble to put them in (which isn't much at all).

 

[CHOMPERS]

i changed the design a little will it work?

Nope. You need that little bit of loop under the tee to trap water in the bottom of the last pipe. without it, the whole thing will lose prime in the event of a power failure. It will not restart.

There is another overflow design somewhere here on MFK that keeps all of the workings outside the tank except for one down tube. Eventually I will be switching to that design because all of the fish poo tends to be at the bottom of the tank instead of at the top. ...just to satisfy the laziness in me...

 

[Lil_Stinker]

i changed the design a little will it work?

This will drain.. Will not stay primed

 

[Dr Joe]

I missed this post, so sorry for the long delay in this response...I added some check valves to my newest overflows and they are the greatest thing since sliced bread. They don't get used much, but when they do they are the handiest things in the world. They are definitely well worth the money and trouble to put them in (which isn't much at all).

Where did you put the check valves? and what kind?

Got a pic or drawing?

Dr Joe

.

 

[IRoman]

what would be a good size pvc piping for a 125? 1"?

 

[rallysman]

Go 1.5" to be safe