coco growers i need help

i dont have pics yet but will this week end, all my big fan leaves are turning brown and drying up, i was using pbp with cal/mag. now i have stoped using that and have been flushing for a week now with no nutes, iv now have canna coco a&b but have not used any yet. i belive this to be salt buildup. as the sample of coir i took was @ 1200 ppm with a ph of 6.3.


Another thing is when i add my ph down it brings my ppms up, as my tap water comes out @ 8.7 ph and has a ppm of 120. i thank that is cuasing the salt build up.

no-one has answered so....I dont grow with coco i do soil. But your tap water sounds like mine and its downright TOXIC! Ph in the high 8's smells like a swiming pool, even my cat wont drink it. i would think that in a medium like coco the "salts" in the water would build up even faster than in soil(which would have more buffers). So i would put some of the blame on your tap water. Make sure you let it sit out several DAYS before use and/or put an airstone in it too. If you drink this water (shudders to think) you should get a good filter. USE a water filter or BE a water filter. Same with your plants medium. Use a filter or your plants pot IS a filter.