Neptune FMM: I'm using 3/4" PVC for return. Should I step down to 1/2" sensor, or up to 1"?

smartwater101 · Apr 4, 2019

3/4" is a pretty common size. It seems really strange that there is no 3/4" sensor option. Especially considering the price difference is 30$ vs 60$ !!

Anyway. I assume stepping down to 1/2" would restrict flow a bit... But is it really enough to even worry about?

Thoughts?

link81 · Apr 4, 2019

what's you flow currently? (roughly)

smartwater101 · Apr 4, 2019

link81 said:
what's you flow currently? (roughly)

Using two syncra 5.0

One goes strait to tank. (~5')

The second goes through chiller, UV and then tank. (Fairly low return on this one)

Depending on what my flow actually turns out to be, I may upgrade both to SDC.

Jason_J · Apr 4, 2019

I would increase the size to 1" for the flow meter. Increasing the size will have no negative affects on performance and will be able to handle additional flow in the future. A 1/2" flow meter could restrict flow as you aren't using pressure rated pumps and will be less useful down the road if you upgrade return pumps.

JDowns · Apr 4, 2019

Jason_J said:
I would increase the size to 1" for the flow meter. Increasing the size will have no negative affects on performance and will be able to handle additional flow in the future. A 1/2" flow meter could restrict flow as you aren't using pressure rated pumps and will be less useful down the road if you upgrade return pumps.

I would agree with this. 1" would be the best solution so you don't compromise the actual flow to the tank. Depending on your piping and installation the meter itself most likely will not give you an accurate true reading of the flow out the end of the pipe, especially running through a chiller, uv, all those fittings, elbows, etc. Not that the meters don't have a place, they are really handy for predictive maintenance if you set a known initial baseline for normal operations.