Is there any way to determine (with a trash pump) how many gallons have been pumped out while draining?


Gold Supporter
TFP Guide
Nov 12, 2017
Central California
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Yikes, your post showed up to me after I wrote my last one. Sounds like Baquacil is expensive and maintenance intensive. I use chlorine, acid, CYA and salt. That's it. I'd be surprised if I spend more than $100 a year. And with my SWG and acid injector, I spend about 5 minutes a week on my pool (pretty much just testing to make sure my gizmos are working). That's it.


Well-known member
Jun 10, 2014
Roseville, CA
I'm considering doing at least a partial drain. The water company I use charges for a minimum delivery of 5k gallons (so I assume I pay for that whether I wind up using it all or not). He can bring 6k to 6500 gallons per tanker. I don't want to wind up having to put in a few hundred gallons (or more) from my well if I'd drain out more than he has with him. So how does one begin to figure out the gallonage pumped out? I can rent a trash pump locally, but - short of eyeballing the level as it goes down - I imagine the pump doesn't have any sort of feature whereby it calculates the rate / gallons pumped out? If so, that'd make things easy. My pool walls taper in all the way around (compared to a square or rectangular shape where the walls are straight all the way down). So that makes it a bit harder to 'guesstimate' the amount pumped out. There must be, proportionately, more water at the top 2-3 feet (where the walls are still basically straight) compared to when everything tapers in (significantly) leading to the drain. Before I'd do this, I need to have a handle on how much to pump out given the 5k minimum delivery and the total 6k to 6500 load. 6 years ago things were easy cause I had the entire pool drained prior to renovation. I really didn't want to drain all of it this time nor have them bring two tankers though I guess that's a possibility. Any advice?
Here is a link to Amazon with a bunch of gallonage counters - probably garden hose size, but it's a start. Also, ask the pump company you plan to rent the trash pump from. They may acutally have one as an option.


Well-known member
Jun 8, 2015
Rocklin Ca
there a lot of factors that come into play size of discharge hose, is there any head pressure, how long is the discharge hose, evry bend causes friction. I used a trash pump to drain mine down about two thirds used an 1 1/4" discharge pipe I just watched it didn't take very long 20K pool. I could ask my neighbor he drains his every year and cleans it with a pressure washer :eek: I guess that's saves money on all those chemicals and running the pump


Well-known member
Jun 8, 2014
Rogers, AR
I don’t have anything to add to your current situation but man I have seen a lot of your posts. Do the conversion and be done with it. You’ll never look back. Seriously, I have my SWG set, run my robot a couple of times a week, brush and backwash once a week and that’s it. Even when I was using liquid it only took a few minutes each day. This truly is trouble free pool care. This is all TFP sparkle😁 after four days of straight rain. It doesn’t get any better than this❤


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Rich D

Bronze Supporter
Aug 3, 2018
As mentioned above, Filling a known volume container and timing it is by far the best way to go for this. Most rental company's have 2" electric pumps. You can use a 55 gal Trash can for a container. If you need to drain faster then just rent a second pump and double your gpm figure from the first