I have an approximately 10 year old, acrylic shell, spa that I have maintained fairly well over the years. Here is my situation that I'm hoping someone can help me with. I change the water (City water, not well water. ) about twice per year and did one about a week ago. After this change my tub's surface was completely covered with this fine, light gray colored sediment. After this refill, I accidentally used my bad batch of chlorine that was not dissolving before I realized it was my bad batch that I forgot to dispose of. (Apparently it got wet and had some chemical reaction and was no longer dissolving in water). I don’t know if the bad chlorine had anything to do with my sediment problem but maybe it did. It happened once before after a refill when I used one of those filters, that someone gave me, that attached to the garden hose. I figured in that case I was getting sediment from the filter and never used it again. I have refilled several times after that incident and have had a bit of this sediment after draining that I shop-vac out as best I can. I have never been able to completely get rid of the sediment but it has been minimal until this last re-fill. This time, while filled, I used a soft bristle bush to brush the sediment off the surface which clouded the water and then after settling for a few hours, left the water perfectly clear and the sediment in piles at the bottom of the spa. Is it possible that the pipes have a large amount of this sediment in them and somehow I released a large amount into my tub this time? If so, how do I remove the sediment from the plumbing PVC pipes? Or, could it be something else that's happening? I’m planning on changing the water again to remove the sediment from the tub but want to avoid this from happening again. I don’t use any kind of water treatment that is used for water hardness and I don’t believe it is sediment from the tap water. It’s too extreme. There’s a lot of it. Any help, theories or suggestions is greatly appreciated.
Added:
Tested water with TDS meter. From spa: 437. From hose where I filled from: 402