Just bought a Hayward Ultra Vac and need a little assistance...

Hi all. I live in South FL and tend to have algae problems, so I manually vacuum my pool once in a while, so I recently got an automatic pool cleaner instead. It works well, but I bought it used so I do not have the regulator valve, which I think I need because even on the I setting, it climbs to the top of my cocrete pool and it sucks air. So, I am going to the get valve (or build one), but I only have 1 suction line to my pump. My pump is a 1 speed pump, so would reducing the suction in that 1 line cause problems with the pump? I don't want the impeller to cause cavitation or anything due to restricted water flow! Anyone else have any experience with this? I know I can get the skimmer plate thing so that the skimmer still sucks water and the vacuum to the cleaner is lowered, but I'm really trying to avoid it because it's 100 bucks...

Any input is greatly appreciated!

I'm going to bump this while at the same time making it easier to understand (re-reading it, it seems complicated!)

Anyways, will restricting the intake flow of water into my pump cause any problems by using a regulator valve for an automatic pool cleaner? The pump only has 1 setting. I'm afraid that by not being able to move all the water it wants to, that pressure will build up or something (maybe even cavitation?)? My inlet is a 1.5" pipe, but the suction is too strong for the auto vac. Would regulating it down to, say... 1/2" cause too much restriction?