cnf276 wrote:The coco coir was rinsed several times in distilled water until the TDS was below 30
That won't work. The coco coir must be soaked for at least 8-10 hours between each draining, and must be soaked in that way for at least 6-8 times before almost all the soluble material is redissolved and removed. The drained water should be discarded. The TDS reading is most reliable when one pours just enough water into the coir to reach the top of the coir, without much excess water sitting on top of the coir.
Rinsing doesn't work because even though after several rinses a low TDS reading might result, there is still a lot of undissolved material in the coir that longer soaking will dissolve and disperse. The water in the coir, if you are using it as a planting medium after just several rinses, may be over 1000 TDS. Even at several hundred TDS, it will damage the plants, give a Flytrap salt burn that will cause the traps to become insensitive, and begin to progressively stunt both the rate of growth and the size of the emerging leaves and traps, until the plant almost stops growing at all, and then (often) dies. Even if one transplants a Venus Flytrap at that stage, the mineral salts are already inside the tissue of the plant affecting and poisoning it, and the Venus Flytrap is obliged to try to outgrow the damage as it sequesters the mineral salts into the existing leaves, which die sooner than they normally would. Sometimes a Venus Flytrap is successful in outgrowing such salt damage. By "salt" I don't mean table salt of course, but any of a large number of soluble mineral salts.
Best wishes and good luck--