My Intex 16' pool came with a 637R, 1000 GPH pump. It has done a great job of keeping the water moving and algae free but it just doesn't have the umph to vacuum the pool without a lot of work and going over and over it and still it left dirt on the floor.
Since I run the ~1/16 HP 637R 24/7 I figured it would not last so I wanted a backup plus something that could clean the pool a bit easier. So I ordered a 633, 2500 GPH Intex pump and received it tonight. Took less that 10 minutes to swap the pumps and hoses. I've read that the 633 is a 1/2 HP pump. I'll measure the wattage and cost to run it over the next 24 hours then run some numbers for an approximation of it's HP.
Here is a picture of the two pumps next to one another for a comparison of the sizes.
My first impression when I turned it on was WOW! Know I "kind of" understand what a more powerful pump does to the water. It doesn't just move it, it churns it. My 637R made a small ripple on one side of the pool but the 633 makes the whole pool ripple. Sure, it's way too big for this pool and the small 1-1/4" ports make the water accelerate faster than needed but it works very well.
I plan on making a poor man's two speed pump. I'll get the tees, one way valves and extra hose to run the two pumps in parallel so I can run the small one full time but turn on the big one when I want to vacuum the pool, add chemicals, clear any algae, etc.
While I ordered the pump, I picked up another little ditty. $280 for the pump, SWCG and adapters for the 1-1/4" fittings (on the pool) from ebay. I'm already tired of pouring so much bleach in this thing every day. I'm sure there is going to be a trade off but hey, it's fun during the discovery phase.
Here is a picture of the pump and SWCG and you can kind of see the water rippling all over the pool. Also, vacuuming works SO much better.