[kgross]

Use the science... Here are numbers that you can duplicate using the RC head loss calculator.

We will use a mag 12.5 pump, with 4 feet vertical head, 3 feet horizontal, and 5 elbows.

One with 3/4 inch pipe
One with 1 inch Pipe
one with 1 1/4 pipe

Then we will run the same numbers but we will use your 3/4 inch spa flex and say that there are no elbows at all and the same with 1 inch.

3/4 pipe with elbows
Total losses are 9.11 feet of head pressure, or 3.94 PSI. with a flow rate of 681 GPH. Process took 43 iterations.

1 inch pipe with elbows
Total losses are 6.82 feet of head pressure, or 2.95 PSI. with a flow rate of 891 GPH. Process took 103 iterations.

1 1/4 pipe with elbows
Total losses are 5.15 feet of head pressure, or 2.23 PSI. with a flow rate of 1017 GPH. Process took 142 iterations.

Now your version with no elbows, should have more flow than larger pipe correct?

3/4 no elbows or other fittings just 7 feet of pipe
Total losses are 7.68 feet of head pressure, or 3.32 PSI. with a flow rate of 816 GPH. Process took 79 iterations. hmm, less than 1 inch with 5 elbows

1 inch with no elbows
Total losses are 5.76 feet of head pressure, or 2.49 PSI. with a flow rate of 974 GPH. Process took 125 iterations. Hmm less than 1 1/4 with 5 elbows

Total losses are 4.61 feet of head pressure, or 1.99 PSI. with a flow rate of 1052 GPH. Process took 155 iterations.

So yes better turns will increase flow, but if you put in larger pipe it makes more of a difference than any type of elbow that you use.

Kim