We've had an above ground pool for 7 years and love it. It has
never turned green on us and we've had no trouble. A few tips from my perspective:
Get a pump that can run on either high or low. With the exception of occasionally adding some chemicals, we run ours on low 24/7. It's affordable and easier to keep chlorine level stable and the pool clean. (Our pump is a Sparco).
Consider an automatic chlorinator. The water goes through the pump, then into the filter, then into the chlorinator, then back to the pool. The only thing you need to do to adjust the chlorine level is to turn a dial. No guessing how many tablets, gallons, etc.
If you use a solar cover plan on replacing it every other year, they just don't last. We quit using one because our pool is in full sun all the time and it didn't seem to make a difference using one. IMO, if you need warmer water, buy a heater, it's probably a better investment.
We use Kleen Pool for an algaecide and never have a problem.
We replace our winter cover every 3 years or so, our winters here do a bit of damage.
The only other things we've had to replace were hoses that dry rotted, they are very inexpensive, and the head to the vacuum, again not very expensive.
Last bit of advice, ask around and use a supplier/water tester that you can trust. We are so fortunate to use the place we do, my SIL was given bad advice from other pool suppliers, and another person we know has to replace his pool because his supplier improperly tested water and recommended things that ruined his pool.
Good luck and have fun! It's easy if you keep up on it and so worth the small bit of effort.
