A 1 inch inlet has a surface area of .785 inch squared.
Two 3/4 inch circles have a surface area of-
2 x pi (r x r)
2 x 3.14 x (.375 x .375)
=.884 sq. inch
If you have two inlets of 3/4 inch, the capacity is greater than the pumps 1 inch thread.
As such a 3/4 barbed Tee is non-reducing.
However, after seeing the photo,,,
A 1 1/2 inch female slip x 1 inch mpt would attach the pipe directly to the pump,,,
And done.
Just seems like a huge performance lever.
That .75 ( ha metric, that slash is hard to find on my keyboard) inch inlet is only .442 inches square.
44.2 Γ· .785 is only 56% of the original one inch opening.
I dare say an intake reduction by half will translate into MORE than half of performance output loss.
Also, I could be stacked full of fishit.
550 gph is very close to 600.
An hour is 60 min. Divide by 60 is 1 minute
600 gallon divide by 60 is 10 gallon.
Should be 10 gallons a minute , eh?
Less 10 percent? 9 gallons per minute.
Try it.
Will that pump fill a 5 gallon bucket in 33 seconds ?
My late night math sucks.
Run that pump for 15 seconds, I will take a wild guess and say that pump will give you
3 litrez