Reel McKoi wrote:

I don't understand how covering 90% will help anything. What work are
you trying to save by covering most of it?

1. To make it look nicer (looking at a blue cover is nicer than brown
water).
2. To reduce evaporation (in this particular construction, pool must
be filled with water to prevent cracks).
=================================
Out of compassion for the fish, if the water is "brown" I would get rid
of them. It has to be stagnant and polluted if no care is being given
(maintained filters, aeration etc). Pardon my curiosity... but what
kind of construction is this pond that it would crack if dry?

Folks, read the original message. He said "pool" not "pond". This is a
very common problem here as many people are walking out on their
McMansions' over-priced mortgages and abandoning house and POOL. The
local authorities, after getting a complaint from the neighbors and
determining that the property is truly abandoned will go in and put
mosquito fish in the filthy stagnant water to help keep mosquitoes down.
Some will spray oil on the water.

Gunite POOLS will crack in the heat if not at least half filled with water.

Chip