As for power, you seem to realize you will be using your pool's pump. If you can, make the skimmer you are using get the most if not all of the suction. If you have a 2 HP pump, crack the drain or the other skimmer some as that is too much for a vacuum hose to keep from collapsing. If they have more than one grade, get the better one. Don't store it on the fence or ground for the sun to beat on it.
Have an Intelliflo variable speed pump so should be able to get good suction-
Construction Note: If the builder used flex pipe on the suction lines, these lines are at risk also! Once those line collapse, they will crease again and again, eventually wearing a hole in them. Always keep the drain cracked open unless you have a 1 HP or smaller pump.
NO FLEX pipe all Schedule40 2 inch for returns
A skimmer plate will fit over the skimmer basket. When using the skimmer basket, don't wait till you lose all your suction or you will crack it.
GOOD Idea
A vacuum hose that is long enough to reach the furthest points with several feet of slack left and a swivel cuff. The swivel cuff allows the hose to rotate as it is extended. This is important as most hoses are stored coiled and the tend to develop a memory for that position. By allowing one end of the hose to swivel, you prevent kinks from forming.
Will find a swivel cuff and good hose
If you have a LOT of debris like leaves, a leaf eater is suggested. It goes on the end of a pool pole and gets a garden hose attached. It shoots water up into a net, generating a venturi under that draws debris up from underneath and shoots it into the net. Another option is a scooping net. Don't over fill it!
Yes Leave's but wont know for sure until I get all the cover off- partially collapsed so debris went in
If it's dead algae, that will be a regular gunite vacuum head. They are rectangular and wheeled. Don't buy the cheapie with plastic wheels and axles. The 12" model, if it has ball bearing wheels and a metal neck (this isn't critical but lasts forever) is the one. Plastic necks are ok but they can break off if too much torque is applied, a PITA. If they only have the higher quality one in the 18" width, spend the money. They aren't cheap but they last and last. Mine are over 5 years old.
The extendible pool pole should be able to reach about 2/3 of the way across with at least a foot of tube left. Don't try to lift a pole when it's fully extended. It will bend and you won't be able to collapse it. It can also crease in middle where it's inner pole meets the outer pole.
Scott