How Are You Measuring Flow for UV?

dangles · Oct 3, 2023

I’ve come across a small handful of threads, and the answers I see are either wildly outside my technical abilities, or jUsT GuEsS (insert Sponge Bob meme). It kind of makes me wonder if people aren’t ACTUALLY getting the benefits of UV….

I do have an Apex, but the reviews for their flow meters look even worse than the ones for their AFS (which is… quite an accomplishment).

So is there really no simple/accurate way to monitor flow?

Stealthreefer · Oct 3, 2023

My quarantine tank/molly tank is 55 and I run a 65 gph pump that is probably closer to 30 gph through a commercial UV(50 watt?I can't remember). Long contact time so everything gets nuked. Own pump own loop.

My main tank I run an 80 wattish with like 550 gph and that's just to keep the refugium algae in the refugium basically and some still ends up in the tank.

Doctorgori · Oct 4, 2023

short answer: I'm guessing ...

I WAS using Neptune Flow sensors but 4 out of 5 purchased have failed to work; support says something to do with magnetic/electrical interference...erh sumthing erh other... blah blah ...
Anyway, following ...I'd like to know also

slingfox · Oct 4, 2023

I just routed the output hose on my UV into a 5 gallon bucket and timed how long it took to fill up to calculate the flow rate. Alternatively you can get a rough approximation of flow rate by looking at the gph of your pump and do some math. My return pumps run at around 80% of the theoretical flow rate due to efficiency loss of the manifold plumbing it feeds into.

CasperOe · Oct 4, 2023

Aye use the age old bucket trick!

Exactly like @slingfox is saying! Far the easiest, cheapest and (..some would argue!) most precise way

ErikVR · Oct 4, 2023

10L bucket and a stopwatch...

JonoH · Oct 4, 2023

Sanking flow meter - still hooking it all up so not sure how accurate they are!

Jon's Reef · Oct 4, 2023

I’ve used several of the apex flow meters without issue. Just make sure to use the same size or slightly larger. Only issue is that the actual sensor body has an odd thread (I believe it is BSPP) so it is hard to find replacement converters once you glue the originals.