To keep the growth at a minimum, some captains use chlorine or bromine tablets in their raw-water strainers, but this can be harmful to the boat’s plumbing, and is usually a never-ending task. Sometimes within days the tabs have disintegrated and need to be replaced, or the strainer baskets need to be cleaned again. If you put too much chlorine in the baskets, flush too often or with too much product, the harsh chemicals can eat through the fittings and develop leaks. Marine plumbing fittings are tough, but not bulletproof. So, just like our own health, being a little more preventative is a better long-term plan.