As an Aquatics Professional, I am always asked about my take on the whole Water Conservation Issue. Water is a Precious resource, and in a time where water conservation is becoming a PRIMARY concern in Aquatic Facilities, we have to take a step back and rethink the approach.
Swimming Pools cannot operate under High TDS (Total Dissolved Solids) loads, as it can lead to undesirable operation. With the Advent of Filtration Systems that lose less water during operations, TDS is becoming a critical issue, especially in areas where Hard Water Tables are present, and Dilution of Bulk Water is not possible.
HOW can operators work around this?
Well, the answers are not easy to swallow.
First off, a pool using High Rate sand Filtration has the longest cycle to reach High TDS, while Vacuum DE is second, while Regenerative DE and Cartridge Filtration are dead last in TDS cycles (meaning they are the fastest to reach 1500 ppm or more TDS). From this, we see that the more water you use, the longer the TDS cycle will be; Thus, Water loss is IMPORTANT in an Aquatic Facility Operation.
So - You work at a Pool With Regenerative DE, and youre now saying, "Im screwed"...Hold your horses there...You have to rethink your operation. First off - Tell your Boss that the WORST mistake they could have ever done is Choose a Regen or Cartridge Filter. If you have had these problems in your Operations, you know what I mean:
If you've been there, You know that your "Duty to Dump" is required; but then you are hard pressed to Not do so...because water Conservation is the expectation of the Owner... The Sad truth is, Water Conservation in an Aquatic Facility is a Pipe Dream; Water loss is a fundamental, and HEALTHY occurrence in Swimming Pools.
So Dumping is your issue...Can We reduce TDS without the Large Water Bills? Sure we can, but it comes at a Cost. Reverse Osmosis Filtration Handily Lowers TDS in Swimming Pools, with considerably less Water loss than by dumpling alone. A Pool can lower its TDS from 2000ppm to 200 ppm, while losing only 20-30% of its Capacity (Water loss is due to the flushing function of the RO system). The only issue is that you have to dispose of that Flush water, and that can be a problem. The water is super concentrated with minerals, and regulations of disposing this water can be restrictive. In most cases, a slow drain of this water into the sanitary system can be achieved, as long as it is accepted by local Waste Water Treatment. Before Jumping the gun, check with your Waste Treatment Plant for suggestions on how to make this work.
In the end, if you want to Conserve water, Sand Filtration uses less water for Operations than Regenerative Filtration, when TDS becomes a consideration. Its important to Triple check the consequences of TDS in your Facility if your are considering a Regenerative System, or Cartridge Filtration.
If you have any questions or concerns, Please feel free to contact me.