PVC Fitting

[Jrapa86]

So I hard-plumbed my return and overflow for 3/4”. I also added an apex flow sensor. It was then I realized, my gph was too low (136gph) for an 83 gallon system. I soon realized it’s likely the pvc diameter rather than my pump. I went out and bought 1 1/4”. However I just bought this ball valve and flow sensor. Luckily I had an extra flow sensor but it’s 1”.

My question is, if I downsize momentarily to a 3/4 ball valve, and then back to 1 1/4, or if I momentarily downsize to fit a 1” flow sensor, does that completely defeat the entire purpose of replacing the pvc to 1 1/4? Or since it is only a momentary thing, I will still have some benefit from 1 1/4 pvc piping?

 

[Reefer Reboot]

Any restriction creates a restriction for the entire circuit.

 

[KStatefan]

Being a smaller size for a short distance will create less restriction then the being the smaller size whole length.

 

[jdiefenbaugh]

The question is a little unclear if you're talking about your return or drain, or both. If your return is 3/4" and you want to use the Neptune flow sensor, then you need to use at least a 1" with reducers. I'm not sure why you would want to use 1 1/4", as it's an odd size for starters, and on an 80 gal tank, I'm not sure why you'd need that big of a return pipe. If it's for the drain, 3/4" at full syphon can handle enough water for your size of tank.