In order to do a visual inspection for organics; particularly when applying iron filters, sulfur filters or other well water treatment filters on non-chlorinated well water; please do the following:
Take the lid off of the back of one of your toilet storage tanks. On ALL well water there will be a film on top of the water. If you can't see it at first you may want to take a strong light and shine it sideways across the top of the water until you see the film. Once you see the film lightly touch the water with your index finger. The film will either "repel" from you finger or it will just lay there. Just tell us which reaction you have and together with few other questions we can determine if you have an organics issue. If you have any sort of chlorine puck or other chemical in the tank, or if the water is chlorinated this test will not work. If you have any iron in your well water an iron bacteria check would be the correct thing to do as well, along with a flow rate check and some minimal water testing.
Visual Iron Bacteria Test: https://waterfiltersofamerica.com/iron_bacteria_check.htm
Flow Rate - Item # 7 on this page: https://waterfiltersofamerica.com/article_faq's.htm
FREE Water Testing: https://waterfiltersofamerica.com/water_test_kits.htm
How to Treat Iron Bacteria: https://waterfiltersofamerica.com/iron_bacteria.htm
Iron Sulfur and Manganese Filters: https://waterfiltersofamerica.com/iron_filters.htm