..This year I am planning on trying a 3" trash pump to suck it out and run it through some sort of filter or screen to let the water drain back in so I don't end up just emptying my pond in the process. Has anyone tried this method and if so, do you have any pointers or things that have worked for you?..
Yes I have.
Starting at the water, use a rigid 6-8' PVC pipe for the inlet, and float it about 8" under the surface with whatever's available. You do this because if the pipe closer to the surface will create a venturi effect, and suck air into the pipe and reduce the pump's efficiency. Floating the inlet will let you either walk the pipe to the algae, or leave it stationary, and rake the algae to the pipe. Both methods work well.
I like using the yellow spiral wired hose between the inlet on the pump, and the PVC inlet. It's more expensive, but it'll save wear and tear on your body. The standard green rigid hose is much stiffer and harder to move around. From the outlet on the pump, I just use 30-40' of hose, and extend it to a gently sloped area that runs off back into the pond. I've used the 2' high erosion fencing like construction sites use to make sure no algae gets back into the pond, but I've yet to have any algae makes it that far. When I've done it, there was only a patch at the end of the outlet. I wait a few days, and just peal it up for the garden. I've only done it with turf, so I'm not sure if bare soil will catch the algae like grass does.
If you're going to be moving around, consider putting the pump on a low trailer or tractor bucket and add a shutoff valve between the rigid PVC, and the rubber inlet hose. This will keep you from having to reprime the pump every time you move it. Just move the pump to the new location, get the inlet hose straighten out in the pond, and press down at the PVC/inlet rubber hose connection. Once that's done, open the shutoff valve and then restart the pump. Doing his will push the air out of the inlet, and the pump will start pulling almost immediately. IIRC, we've applied 30 tons of gypsum in a friend's 3 acre pond using this same method in less than 3-4 hours. Only difference was the inlet and outlet hoses were swapped.
Just random stuff, but all pumps require a certain percentage of water to operate correctly, so let the hose pull clean water between the heavy algae pulls. If algae's a problem right now, I might do it before filamentous algae gets really started. Denser weeds including FA can back up at the flapper valve at the inlet side on the pump housing itself, and require cleaning. It's a PITA if this happens, but it shouldn't with just algae. FYI, coontail's the worst about this.
Tilapia stocking numbers can be lower if you are able to remove algae now. By summer, it can take double or triple the amount of tilapia to control an aggressive algae problem.
I'll look for pics later if that helps.
Oh, welcome to the forum.