I've  been running 3"hose for about 10YRs now, right off the 4to3"reducer and i'm going to run 3" pipe in front of the  3" hose . do any of u guys do this for 3/4 rock pumping?

The line pump guy I use has pumped 3/4" for me through 75' rubber.He changed the mix at plant on me,which was ok.I would say find mix designs that work for you in 3,3500,4000 ranges.Another point is pipe doesn't swell like rubber,which should give you more pumping ability.This could be more of a trial and error,the expense of pipe.

Doesn't work too well here in NJ though I've done it.  It takes a good mix.  We just use 4 inch line for 3/4 and 2.5 inch for 3/8 mixes.

There are ¾ mixes and then there are ¾ mixes. The only way to REALLY know what you are dealing with is to ask the folks at the batch plant what A.S.T.M. size coarse aggregate they are using. By ¾ - does that mean that the aggregate is 100% passing a 1” screen [A.S.T.M. # 6 – 67 – 68] stone? By definition they are all ¾, but given the choice, and using 3” pipe, I would personally prefer the A.S.T.M. #68.

So I guess my question is….. What ¾ ARE you referring to?  ;~)

here we use 3/4 3000 pump mix.the rock is a little more rounded & higher PSI makes it easier to pump

ACPA rec's min 3X's the size of agg. Schwing rec's min 4X's. For 3/4" this is 2.25" and 3" respectively. Personally I pump 100% 3/4 through 2.5", and some companies have "blend" mixes that are what they call 1" minus mix. I have pumped tham all with 2.5" and 3" rubber, up to 250' so far. Just my experiences...

another thing to remember is that friction in rubber is 3X's that of pipe. Might consider running your pipe first, then your hose ;)