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Do you have difficulty maintaining chlorine or bromine levels on pools using variable speed pumps? This is your how-to guide for effective variable speed pump sanitation with Powerclean™ Ultra VS. 


There are three primary elements to keeping a pool clean and healthy that every service tech knows: circulation, filtration and sanitation. Each of these must work together for optimal performance to keep a pool clean and clear, with happy swimming customers.Variable speed pumps are a great addition to a pool, with huge energy savings. A single speed pump can account for as much as 25% of yearly residential energy use. With a variable speed pump a pool can filter and circulate at lower speeds leading to real yearly savings for the homeowner.


Get the maximum flow!

That leaves the third pool care element to consider: sanitation. In the past few years, many consumers who are using variable speed pumps have noticed lower chlorine levels in their pools using a variable speed pump at lower flow rates and/or elevated back pressure when running at higher speeds. For service techs this can lead to big problems keeping a pool properly maintained.

According to CMP Technical Reps, calls come in regularly from pool techs having issues with standard pool chlorinators working with variable speed pumps. The calls all outline a similar condition and most boil down to the same issue: chlorine isn’t flowing into the pool at the proper rate.

What these service techs and homeowners have described is that a pool using a variable speed pump is going to reduce system flow at low speeds. The low speed doesn’t create enough pressure to force water through the chlorinator feed tube, resulting in no chlorine flowing into the pool. Instead, the water bypasses the feed tube and simply passes through the chlorinator untreated.

Most pool chlorinators, including a standard Powerclean Ultra, requires system flow of 40-50 GPM to even begin registering flow inside the chlorinator.  For optimal chlorination higher than 50 GPM is ideal. A typical variable speed pump can operate as low as 20 GPM when running at lower RPM settings. Without chlorine flow, the feeder is ineffective. The low chlorine levels lead to an unsafe and unsanitary pool that is difficult to maintain.

Alternatively, some chlorinators that retain some chlorine flow at lower systems speeds create elevated back pressure as a trade off. In laboratory testing, these units generated as much as a 3.5 PSI pressure drop at the feeder. Elevated back pressure leads to poor system performance. A feeder is typically the last item installed in a system. This high back pressure can affect all equipment installed before the chlorinator including heaters, filters and pumps.


For builders and homeowners using CMP Powerclean Ultra Chlorinators, these problems can be corrected with the new Powerclean VS Kit. A system operating at 60-70 GPM has a chlorine flow of 0.4 – 0.6 GPM. With the VS kit installed, chlorine flow will begin at system flow rates as low as 20 GPM (typically the low “RPM” settings on a variable speed pump). Chlorine flow of 0.6 GPM requires only 30 GPM system flow. At 40-50 GPM (medium RPM speeds) the chlorine flow is up to four times that of a feeder without the VS Kit.

The VS Kit is engineered to accelerate the chlorine flow without trading off high system back pressure. At typical variable speed system RPM speeds, the VS Kit generates less than 1 PSI of pressure drop at the chlorinator. The VS Kit can be installed without negatively impacting the rest of the system or effective equipment efficiency.



The Powerclean VS Kit can be installed in any Powerclean Ultra or Econ model chlorinator. To install in an existing Powerclean Ultra chlorinator, remove any chlorine or bromine from the chlorinator and turn the Powerclean control valve to the closed position (counter clockwise). Always use caution when handling chlorine or highly chlorinated water. Turn the pool system off and wait one minute for excess water and fumes to drain from the feeder. If necessary, close other pool valves to prevent back flow or excess drainage when the chlorinator is removed. Drain any remaining water from the chlorinator using the plug located at the bottom of the chlorinator. Now you can disconnect the chlorinator using the two unions attached at the inlet and outlet.

The Powerclean VS Kit includes a VS Inlet Adapter (1), VS Cone (2) and VS Outlet Adapter (3). Install VS Outlet Adapter in the Powerclean outlet. Press firmly in place. Next, install the VS Cone into the Powerclean inlet. The cone will press fit over the inner tube inside the chlorinator. Last, install the VS Inlet Adapter into the Powerclean inlet. Press firmly in place.

Once the kit installation is complete, re-install the Powerclean Chlorinator using the union connections. Don’t forget to put the drain plug back in place! Fill the feeder with water, making sure to bleed out any entrapped air in any of the lines. Replace chlorine tablets and re-open the control valve to the desired setting. To ensure maximum effectiveness, the pool should be properly conditioned and the chlorine residual should be 1.0 to 1.5 ppm.

With the VS kit installed, chlorine flow will begin at system flow rates as low as 20 GPM (typically the low “RPM” settings on a variable speed pump). IMPORTANT: The Powerclean VS Upgrade Kit is only intended for systems with 2-speed or variable speed pumps where the system flow is less than 50 gpm at the lower speed. For systems that regularly operate above 50 GPM the Powerclean VS Kit is not recommended.


When dealing with chlorine or bromine, always use appropriate precautions. Use only Trichlor-s-triazinetrione OR Bromine tablets – slow dissolving type. Never mix Trichlor or Bromine with Calcium Hydrochlorite, with other forms of concentrated chlorine or with other chemicals. Fire and/or explosion may result. Never use oils or grease to lubricate o-ring. Oil in contact with Trichlor or Bromine may result in fire.

The Powerclean VS Kit is available stand-alone and also pre-installed in the Powerclean Ultra VS.



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