Fine brown sediment on pool floor

This the second season with our new pool. We have had fine brown sediment on the pool floor this entire summer. The sediment can be "kicked up" and the floor of the pool looks clean. The sediment was not being filtered by our vacuum (using the pool filter) so we purchased a robotic vacuum which actually works quite well. However, two days later most of the sediment is back. PLEASE HELP!!! What do we need to do to get rid of this? We will need to close the pool for the winter soon. I'm afraid of what the pool might look like when we open it next spiring. Thank you for your time!!! rsk111

Hello, and welcome to the forum!!

Barring an algae bloom, your brown sediment is most likely dirt/pollen/dust that blows into the pool and eventually settles out on the bottom, especially if it keeps settling back into the same places each time. Every pool has a certain amount of this, and there's not much you can do other than to vac it to waste or keep it stirred up in the water so your filter has a chance to get it.

The other two possibilities are 1)iron settling out of suspension, and 2) algae trying to grow. If you don't have iron in your fill water, then you can rule out #1. To test for #2, try testing your chlorine at night after the sun is off the pool and again in the morning before the sun hits the pool. If you lose less than 1 ppm of chlorine in that time, then you can pretty much rule out #2 and assume it's just dirt. If you lose more than 1 ppm chlorine during that time, then you have algae trying to grow and you need to shock the pool.

Follow Jan's suggestions above. But, my guess is that it is just dirt. I vacuum my pool and it looks spotless. But a few hours later when there is nobody swimming and the water gets still, some of the dirt that was just in suspension in the water and thus not sucked up by the vacuum, falls back to the floor. My pad underneath my liner was taped together with some sort of tape and the dirt in my pool wants to settle in the lines created by the tape seams. It is no big deal and like Jan said, there is really nothing you can do about it. Unfortunately, there is no way to keep a pool perfectly spotless. Your best bet is to just go swimming a lot! When you are in the pool, it will get stirred up and you won't be able to see it!

Hey, you can solve the problem the easy way, by letting your pool get a little cloudy. Then you won't be able to see the brown dust. ;)