| Contaminant | Source | Effects on plants | Suggested System |
| PPM of TDS | Well/Spring Municipal/ City | Water with high PPM of TDS (total dissolved solids) has unknown contaminants that is the key cause of nutrient lockout and deficiencies in plants. | Merlin-Garden Pro Stealth-RO100/200 |
| Chlorine | Municipal/ City | Biocide that kills beneficial bacteria, fungi and micro-organisms. Any healthy organic or bio-hydro garden is chlorine free. If you are using or brewing compost teas or bio-extract solutions, removing the chlorine is essential. | Small Boy Tall Boy-Outdoor Merlin-Garden Pro Stealth-RO100/200 |
| Chloramines | Municipal/ City | Biocide that’s a combination of chlorine and ammonia and is much more stable than chlorine. It will not dissipate by bubbling or even by boiling off. Can only be removed by proper filtration. Toxic to beneficial bacteria, fungi, micro-organisms, fish and amphibians. | Small Boy Tall Boy-Outdoor Merlin-Garden Pro Stealth-RO100/200 |
| Hardness | Well/Spring Municipal/ City | Dissolved calcium and magnesium that forms scale on equipment and tubing. Too much of either of these in your water and you are locking out key nutrients to your plants. Your plants will be unable to feed properly and will exhibit deficiencies. Pipes and equipment can eventually get clogged and fail. Mineral hardness is the key cause of water problems in hydroponics and other gardening systems. | (less than 10 GPG)- Merlin-Garden Pro Stealth-RO100/200 (more than 10 GPG)- Softener with RO system |
| Fluoride | Municipal/ City | A hazardous waste product that is present in all municipal water. This is a toxic substance to humans and plants. Thirty-four enzymes in plants are affected by fluoride as is seed germination. Enzyme additives will not do their job properly with fluoride in the water. | Merlin-Garden Pro Stealth-RO100/200 |
| Volatile Organic Compounds | Municipal/ City | Some VOC's are known or suspected carcinogens. Trace amounts of these can end up in the plant’s tissue, flowers, and fruits. | Small Boy Tall Boy-Outdoor Merlin-Garden Pro Stealth-RO100/200 |
| Iron / Sulfur | Well/Spring Municipal/ City | Water containing iron or sulfur may have a metallic taste and an offensive odor. Nutrient lockout, algae growth, and equipment staining can be results of too much iron on the water. | Merlin-Garden Pro Stealth-RO100/200 Softener |
| Pesticides/Herbicides | Well/Spring Municipal/ City | Local agricultural areas may be leaching harmful contaminants into the ground water. These can end up in your water supply and in your plants. | Merlin-Garden Pro Stealth-RO100/200 |
| Bacteria | Well/Spring | Local water sources may be affected by animal and human waste. These toxic substances can be found in trace amounts in fruits and flowers and can be harmful to humans. | Merlin-Garden Pro Stealth-RO100/200 UV Sterilizer |
| Nitrates | Well/Spring Municipal/ City | Run off from agriculture, animal yards, etc. Toxic substances that contribute to over-nitrification and algae growth. Causes “blue baby syndrome”. | Merlin-Garden Pro Stealth-RO100/200 |
| PH | Well/Spring Municipal/ City | Water that has either too high or low PH will not allow nutrients to be absorbed properly and can be corrosive to equipment. Adjusting PH may be difficult due to fluctuations in levels. | Merlin-Garden Pro Stealth-RO100/200 |
