GmB

From a couple of week we are seeing this brownish stuff which is accumulating on the bottom and on the walls of our pool. Brushing it out seems to easily dissolve the thing but after the next pump cycle it is there again.
Our maintenance guy, who comes every other day, seem to be unable to get rid of it. The pool is fairly new (4 months) and we obviously called the constructor which blamed the maintainer and told us that  the chlorine/ph level wasn't optimal and that we could fix the problem adding chlorine and letting the pumps run for a whole night.
We asked then to the cleaning guy to do so but it looks to me that more the pumps are running more this brownish stuff is piling up.
I initially thought is was sand but i am now thinking about algae.
At the moment the pumps are running from 36 hours and the thing is there as never before.
We really do not mind about paying the electric for the pumps but this is obviously not going to work and all we want is the pool clean now.

Does someone know how to solve this problem or point me to a professional able to sort out this problem?

Just found this beautiful insect in the skimmer of the pool.
That's one of the strangest creatures i had ever seen,
It looks like a micro turtle embedded in a dish and has a very shiny golden color
Does anybody happens to know what is it?

Our cat brought us a small snake (30-40 cm) as gift this morning.
I never seen this kind of snake around before, any info?