Should I Pre-Filter the Water?
Many of our clients ask us whether it is necessary to filter the water before feeding water to the Misting System. In most cases, the answer is no, as our systems are designed with a 10”, 5 micron filtration system built into every pump we make. This usually takes care of the debris that can cause nozzles to fail.
However, if your water is extremely “hard”, there are two commonly recommended ways to pre-filter the water.
Standard Water Softening:
Water softening is the reduction of the concentration of calcium, magnesium, and certain other metals in hard water. These “hardness ions” can cause a variety of undesired effects including interfering with the action of soaps, the buildup of lime scale, which can foul plumbing, and galvanic corrosion. Conventional water-softening appliances intended for household use depend on an ion-exchange resin in which hardness ions are exchanged for sodium ions. Water softening may be desirable where the source of water is hard. However, hard water also conveys some benefits to health by providing dietary calcium and magnesium and reducing the solubility of potentially toxic metal ions such as lead and copper.
This is the preferred method for pre-filtering the water before feeding the misting system. Standard water softeners will do the job in 99% of the cases and it is the most affordable and simple solution.
Reverse Osmosis (R/O) Systems:
We often hear that other companies recommend these systems but we do not recommend them for the following reasons:
Definition: Reverse osmosis (RO) is a membrane-technology filtration method that removes many types of large molecules and ions from solutions by applying pressure to the solution when it is on one side of a selective membrane. The result is that the solute is retained on the pressurized side of the membrane and the pure solvent (water) is allowed to pass to the other side. To be “selective,” this membrane should not allow large molecules or ions through the pores (holes), but should allow smaller components of the solution (such as the pure water) to pass freely.
- Household reverse osmosis units use a lot of water because they have low back pressure. As a result, they recover only 5 to 15 percent of the water entering the system. The remainder is discharged as waste water. Because waste water carries with it the rejected contaminants, methods to recover this water are not practical for household systems. Wastewater is typically connected to the house drains and will add to the load on the household septic system. An RO unit delivering 5 gallons of treated water per day may discharge anywhere between 20 and 90 gallons of waste water per day. For household use, however, and based on consumption of half a gallon per day, this may amount to less than a toilet-flush per day. So in order to provide sufficient output for even a basic misting system, a larger scale system is needed.
- Large-scale industrial or municipal systems have a production efficiency typically 75% – 80%, or as high as 90%, because they can generate the high pressure needed for more efficient RO filtration. On the other hand, as efficiency of waste-water rates increases in commercial operations effective removal rates tend to become reduced, as evidenced by TDS counts. Large scale systems are complex and expensive.
- Due to its fine membrane construction, reverse osmosis not only removes harmful contaminants that may be present in the water, it also strips many of the good, healthy minerals from the water as well, thereby making the water quite acidic. Reverse Osmosis water is, in fact, so chemically unstable and acidic that in many countries national plumbing codes restrict water that has been filtered via reverse osmosis from being reintroduced into copper pipes due to its corrosiveness on the copper. This also has implications for reverse osmosis filtration systems that use steel storage tanks, as the acidity of the water can lead to the steel rusting over time and contaminating the post-filter water. Because of the corrosive nature of the water emanating from the R/O System, all pump parts making contact with the water must be made of 3/16th stainless steel. This increases the cost of the misting system dramatically.
Below see the diagram showing the basic structural requirements of Reverse Osmosis, standard Water Softening, and no pre-filtering (most common solution)