Simply Koi and More Koi

i am running Laguna Powerjet Max Flo 6000 to a clover leaf cl2 the pump seems to have a little to much flow can i fit a dimmer switch or a ball valve ,i dont want to fit the ball valve as i might harm the pump as it will be trying to forse the water through but if i fit a dimmer switch all i will do is slow the pump not sure on the amps the switch will hold as well .
i have not done any thing yet i was hoping somone here might have done all these already but i am keen on the dimmer switch idea
also the laguna range has Universal Fast Coupling for 3/4", 1" & 1-1/4" diameter hosing i can remove the tail on the pump and put a laguna y spilter straight on the tail so i can cut one tail at inch and a quarter and fit the hose to filter and leave the other tail as is at 12mm and let the pump put about 1/3 of the water in the pond but it will make the water go in my pond move fast as it is round so the koi will need to keep moving with the flow will they mind this option
at the moment the third bay is with alfrgrog and three layers of foam are starting to make bay two back up so its filling over the lip and wene the summer gets here again the pond will be producing more muck so the filter will be getting more so if i can slow it down it will give the filter time to do its job as i am turning the water over ever hour with this as i have 1300 gallons
i dont want to get a smaller pump as this was new three months ago but if i have to i will

Hello
one way you can reduce the flow is adding a T piece to the pipe ...and lose some of the flow back to the pond .. and the remainder will go to the filter ..add a valve on the end of the pipe then you can regulate whats going back to the pond.. close the valve then more will go to the filter
I have done this a few times when i have HAD to use a bigger pump ..you can add the T close to the pump under the water level and use the shut of valve to regulate the flow that it going to the filter ...that way you wont be stressing the pump and you will get the correct flow to the filter ..might take a little trial and error but..you should get it sorted
i run a 5000 lph pump on my CL2 and that works great .. 6000 might just be overdoing it...
regards
Max