• Rob

    I know this an old posting.

    I used the FlowViz on a commercial pool we built this past summer.

    We had 3 separate cartridge filtration systems with FlowViz check valves on the influent and effluent sides of the plumbing.


    I am very impressed with the product. First it's very easy read. The valve body is exactly like a Jandy valve body which allows you to use an existing valve body and just switch out the "guts".

    It accepts either 2" or 2.5" plumbing configurations. On our plumbing we used 2.5"

    Unlike a typical (floating ball type) flow meter which clogs very often, you won't have this issue with this product. Plus, the typical flow meter is something that can easily be knocked into or broken as it sticks up from the plumbing.

    We installed a sophisticated variable frequency drive for each motor that allowed us to set the RPM's of each motor for maximum efficiency. In order to achieve this, we needed to know the flow rate so we could set them for the proper turnover rate. The easy read out on the FlowViz allowed for us to perform this operation.


    Hope this helps.


    • Good for you for seeing the ease of use of these units, Kevin!  We too have been impressed with how easy they are to use and install.

      In case you do not know, they also make a unit for 1 1/2" plumbing (FV-C-15) as well.

  • The Flow Viz are an awesome tool and I don't see mentioned the use I first thought to put it to. I can put a myriad of flow-meters in a system but one elusive and very important place is the backwash line on a sand filter. If everyone sized equipment properly it wouldn't be such an issue but they don't and the media, laterals and structure all take a beating in many cases with excess flowrates. Teaching someone to use a pump outlet valve to throttle the backwash flow to the correct GPM will improve a lot of systems.

    Commercially we can install Griswald valves but often they are seen as an unneeded extra cost ...... unfortunately.

    • Hi Rick,  have you any figures on the sort of backwash flow rates you have encountered?  Over in Europe we don't tend to have pumps as big as the ones spec'd in the USA. We have them available but we generally don't feel the need. 

      The correct size of flow rate?  I base this on the lower drag figures for the backwash pipe being in most cases shorter etc but it is important to get enough bed expansion to actually separate the grains of sand. If the flow rate is too high it will surely wash the media out of the filter so that would be the first indication that things were to powerful? 

      Some of the cheaper filters have very poor backwash due to poor laterals (this is the biggest difference I can find between filters)  Early this year I had to strip a filter which contained very muddy media, despite the last operation before close down previous winter of backwashing the media to lower the water level, so much longer that a usual backwash.

      Poor backwash which leads to dirty media is just wating for trouble, the media must be clean. I am going to start work on filter lateral or bottom pipe arrangements early next year in an attempt to reduce the frictional losses through filtration which will also improve the backwash although I also air scour as that saves water and works really well.


      • Hi John, I think the generally accepted norm and even maximum flowrate for backwash is 15gpm per sq.ft. I seem to remember tests from many years ago where filters run in both filter and backwash modes. The pumps were slowly ramped down and stopped and the water slowly drain out, Then the tops were opened and the beds were inspected to look for evenness etc. We brought filters in long ago and had to do these tests and it was decided to change the diverter head arrangement in some to improve results.

        Re: Muddy media. Sounds like too low of a flowrate and simply didnt clean the bed. Also could have been over backwashing at some time which led to partial lateral plugging which would lead to channeling and eventually any flow path would be inhibited. In that case as you pull all the media out you can see how deep the sand bed was plugged etc. Now you would usually use a big sucker truck to get the sand out. We used to have to cut tanks apart and/or shovel the media out so we became intimately familiar with the sand beds LOL Surprising when you can open up an ancient filter and still very nice sand deep in.

        • Thanks Rick,  What diverters did you find improved the situation?  Yes the 15gpm/sq ft is a sort of recommended max which for  Triton TR60  (3.14sqft) is around 47 GPM  which once I have converted to metric is 10m3/hour which is quite low and I would more commonly increase that. 


          The mucky media filter was one of those cheap blow moulded ones and came with partially moulded laterals so the flow rate you would expect as the laterals were poor quality. 

          BTW the mucky filter had been running for 2 years with a multicylone pre filter, so draw your own conclusions!

          I still suck out the sand with a powerful shop vac as the biggest filters I work on are TR140's


          • I havent for a while but commonly did filters that had 10,000 lbs of sand and gravel in them.

            I just did a TA60 and replaced a TA40 with a TA50 on same job. Would have used a TA60 had room allowed. I actually used FloVis on them and see the TA60 was doing a little better than 50gpm, not bad. Will start the TA50 today and see but pretty sure its going to be the same. I could see the sand blasted interior of the TA40 after I cleaned it out. Clearly over backwashing, also light on sand. Of course I dont mind that at all when I have to drag them out of a crawl space to empty them LOL

            As for diverter improvement, I think it was more or less increasing the numbers to decrease the flow or velocity. Much like the TR140 and TR140C you might see.

            • Understood Rick,  Do you have the Lacron filters in the US?  they have multi diverters on some filters larger than the 60's or commercial and the lateral arrangement looks much better too. I may well be swapping my allegiance, another bonus is they don't use owner specific connections, rather the standard pipe threads so money can be saved there too.


              • Not familiar with Lacron, but then I'm in Canada LOL. Larger commercial filters I've done, Astral, Mermade, Stark and more. Residential I seem to prefer Pentair these days, used to go with Jacuzzi before they priced themselves into oblivion long ago. Some have stronger points than others but at the end of the day, none of them work well with bad flowrates. And all do if attention is paid to proper sizing and flow.

                Owner specific connections are a pain. Look how many types of valves and unions there are and how difficult it can be to match a collar at times, even within the same brand when they decide to swap molds or such.

  • Quick add to the thread:  My business partner and I both have FlowVis on our individual pools, and we have sold hundreds of them (just placed another bulk order in fact).  They are a great addition to any pool, and are almost required on any pool with a VS pump to really know what is going on.  We have had zero complaints or returns (many of the sales are eCommerce sales) and are completely happy with the product.  Additionally, these valves are NSF rated, making them compliant in any pool.

    Just my .02 to the thread. 

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