Maxi-Jet powerhead question

[spikehs]

Hello,

I have a maxijet 600 attached to my kalk reactor and it doesn't seem to mix the kalk all that well (I think the pump might be on the fritz despite my cleaning).. so I want to upgrade it to the maxijet 1200... however I was wondering if the intake/nozzel bit (the part the screws off) is a standard size? As it is glued into the kalk reactor and i don't want to take it off particularly... thanks!