1. Opaque plastic water tanks remove most of the sunlight from accessing your water, this reduces photosyntheisis and slows the growth of algae, some bacteria and viruses.

2. Water tank materials of construction impact the long term quality of your water. Consider degradation of both tank materials and linings a potential for adding harmful materials to your water. i.e. lining materials, rust, off gas (styrene in fiberglass tanks). Water tank material selection make all the difference. FDA - NSF Polyethylene is proven to add nothing to your water...

3. Reduce the stagnation potential and its resulting effects on water quality, by designing "first in, first out" piping systems on your tank.

4. Semi-annual preventative maintenance programs should include but not be limited to, removing accumulated particulate, sludge, reviewing and maintaining interior and exterior coatings, process connections and gaskets etc.

5. Vent Air insures that will neither create a vacuum or over pressure the tank. Pumping water from the tank requires air to replace the water and pumping water into your tank requires that the air be displaced, be aware of the potential impact of air borne particulates, and filter it out, bag filters, HEPA filters get the job done.

Venting air  from and into your tank is a Critical issue in your tank design. A rule of thumb is "your vent size should equal your largest process connection". This will insure adequate air flow as the liquid coming into the tank displaces air (escapes) and air into the tank (inflow) as liquid is pumped out of the tank. The results of not properly venting your tank can be catastrophic.

Design control elements for vent air will exclude bugs, birds, small animals and air born particulate the water tanks. Use a screen, bag filter, HEPA filter, conservation vent, either singular or a combination to vent air and exclude these foreign materials.

6. Water analysis will indicates the potential need -requirement to include some remedial chemistry to increase -maintain the quality or bring your water into State and Local compliance. Chlorine residual or comparable treatment, Ph controlling chemicals and sequestering chemicals, fluoridation, as examples. If you must treat, consider the potential impact of these chemicals may have on your water tanksystems. Again consulting local health departments will inform you of these statutory requirements for what the quality of your water must be, as well as inform you of maximum ppm levels of specific chemicals that may be present.