How to Understand a Water Quality Report

While some cultivators are lucky enough to enjoy a clean and reliable water source that’s readily available, that’s not the case across the country. According to NASA’s recent satellite data, 21 of the world’s 35 largest underground aquifers are losing more water than is being replenished, and reliably clean drinking water can no longer be taken for granted.

One of the worst mistakes a cultivator can make is to invest money into a garden, but neglect the issue of the water supply quality, perhaps the most important resource to having a genuinely healthy end-product.

Even if you believe your geographic area has “good” water, not investigating the water quality and irrigating your plants with contaminated water could choke their potential and undermine an otherwise perfectly engineered operation. If you wouldn’t drink the water at your house or cultivation facility, why would you give that same water to your high value crops?

Obtaining a water analysis to determine the source water quality helps cultivators decide if using a water treatment system would benefit their operation. Municipalities usually provide free water reports, however, it is up to the individual to test private water sources not supplied by the city. The EPA recommends testing household wells at least once per year, as the water in underground aquifers can fluctuate with the seasons.

Water Quality Basics

The overall water quality is usually based on the amount of total dissolved solids, or TDS, and is measured in parts per million (ppm) or mg/L. Dissolved solids are so small that they remain suspended in molecular, ionized, or micro-granular form and need to be removed at sub-micron levels using nanofiltration, distillation, or reverse osmosis.

However, the TDS is a generalized point of reference, as some contaminants can exist in even less than one part per million and can cause detrimental problems for your crops. For example, if boron is present in over 0.5 ppm, boron-intolerant plants may become stunted, with drastically decreased yields.

Another key indicator of water quality for plants is the total hardness, expressed as calcium and magnesium in grains per gallon (GPG) or ppm. With too much hardness, nutrient formulas can be thrown out of balance, and plant deficiencies or nutrient lockouts can quickly become a major problem.

Any water source with over 50 ppm of TDS of hardness should be purified. 50 ppm of hardness translates to three grains per gallon and is considered soft water, which few facilities have straight from the tap.

Getting Your Water Tested

The first step to getting your water tested would be to determine if your water source is supplied by the city, a well, or some other source like a pond, spring, river, or rain. Each type of water source presents a different challenge when it comes to choosing the right filtration method.

The type of water filtration system that is ultimately best for well water treatment may not be the same for municipal water users. While most well and spring sources require a sediment filter to remove sediment, city dwellers need carbon to remove chlorine and chloramines.

City

Cultivators using microorganisms such as beneficial bacteria, fungi, nematodes, mycorrhizae, and trichoderma must have chlorine and chloramine-free water for those beneficial microbes to survive and flourish.

All municipal water contains chlorine and/or chloramines as they are both powerful biocides, meaning they are designed to kill bacteria and sterilize water distribution lines.

Trace heavy metals like lead, copper, or iron from aging city water distribution pipes are becoming more common and even impacting human health like the lead present in Flint, Michigan’s municipal water. Additionally, hormones, pharmaceuticals, and all kinds of other toxic materials are increasingly making their way into the national water supply.

Well

Water from well or spring sources are often high in minerals such as calcium, magnesium, sulfur, or iron. Giving water with too high of levels of these minerals to heavy-feeding plants will contribute to nutrient lockout and lead to deficiencies. Wells located in industrial agriculture sectors can become contaminated with high nitrates, pesticides, or herbicides used in modern farming practices.

How to Interpret a Water Quality Report

The following table shows the most common contaminants found in water, their sources, what harmful effects they can have on plants, and the concentrations that would start to affect plant health or facility operations. As one can see, many unknown dissolved minerals in an untreated source water can have the potential to damage high value crops.

Using reverse osmosis to filter source water is the single most efficient, economical, and reliable way to ensure the removal of 98 per cent-plus of all contaminants mentioned above.

As reverse osmosis technology continues to advance and new regulations go online, several simplified water filtration solutions for commercial and hobby growers are now available.

These systems ensure consistency and reliability of water input and are critical to the professional grower. Already have access to excellent source water? Consider yourself lucky.

The rest of the country is having to deal with increasingly complex and sometimes dangerous water contamination issues as seen in areas like Flint and Corpus Christi, Texas. Remember, if it’s not healthy for humans, it’s probably not healthy for plants.