How to reduce animal growth inside raw water filters


After extensive research, design, and many years of use and operation, ZRD has solved a very common problem - Growth Inside RAW water Filters. Raw water filters due to their design allow marine organisms (such as barnicles, tube worms, ...) a very wonderful environment for existence. From this breeding ground, they spread through the connect items ( heat exchangers for air conditioning and engines, raw water intake for water makers, heads, ...).

What we have found is that if you place a few (we use 4) 3/8" copper tubing inside your raw water filter, enough leaches into the water flow to radically inhibit growth. This is exactly how good copper bottom paint (such as Trinidar 75 or SR) does it. The simplicity of this solution was "staring everybody in the face". It is almost too good and simple to be true, but it does work. Depending on the clarity of the raw water, occasional raw water filter cleanings are still required. This method has no bearing on the sediment deposited into a raw water filter. However, only a small clean out with a baby bottle brush and occasional removal of large particulate (such as leaves or other floating trash) is all that is usually required. Again, depending on local water conditions, every 2-4 weeks the copper tubes inside the raw water filter need to be "green brillo'd" to remove the built up surface oxidation in order to keep the copper tubes in a good working state. This is just like a surface rub/wipe down on bottom paint that needs to be done every so often.

Some people use Bromine tablets, but this is a poor choice from our research. It sometimes work, but if you look at the chemical makeup, even the best formulation we found is at most 66% Bromine and still has 33% Chlorine. The chlorine will cause long term damage to some equipment and should be avoided - Not to mention the expense on a weekly basis.

Before view of Raw Water Filter with barnacles Pictured at left is a typical installation of a Raw water filter (Groco model ARG750 ) showing barnicle growth.  

After view of Raw Water Filter with no barnacles     Copper Tube(s) put inside Raw Water Filter Pictured at left is the same filter after being cleaned with our heat exchanger cleaner and running 4 weeks with copper tubing (adjacent photo) installed. NO barnicle growth is seen. Raw Water Heat Exchanger Cleaner

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