No - that's what "powers" the vacuum!
Rather than pull water from the pool surface, which a skimmer normally does, your new plate and hose will allow you to pull water from wherever the other end of the hose is. The plate pictured above may or may not work due to the right angle fitting on it. For some pools, it works great to use it and feed the hose out of the skimmer opening into the pool. Mine requires a plate with a fitting that points straight up, so the hose comes up out of the skimmer, and loops back down into the pool.
Not mentioned - but you do have a "head" for the other end of the hose, and a long pole to attach to the head, right?
Here's a random video about some of the different kinds of heads you can get:
Have the head and the pole attached to the hose when putting it in the pool. Feed the remainder of the hose vertically, slowly, into the pool so it fills totally with water. Then attach the other end to the plate in your skimmer. (You're getting as much air out of the hose as you can)
Then set the valves as poolstored noted, and turn on the pump. Move the head around with the pole to suck up whatever you need to. With the gray valve as pictured, the dead algae will go into the filter. If the filter pressure rises, stop vacuuming and clean the filter. Then keep on vacuuming. If a lot of dead algae, you may want to have the gray valve set so the "off" is over the pipe to the filter. This will send the water/algae out your blue flexible waste line. Note this will lower your pool, and can use a LOT of water that needs to be replaced. So only use that option for really, really dirty conditions.
