I use the following calulator (Online Compressed Air Pipeline Pressure Drop Calculator - Imperial Units)...https://www.engineeringtoolbox.com/pressure-drop-compressed-air-pipes-d_852.html
Using 1 CFM, 200' hose, and 5 psi pump gage pressure...
A 200' long piece of 3/8" ID tubing will eat over 3 psi (You don't want this),
1/2" wants 3/4psi (not bad),
5/8" ID line only wants about 1/4psi (much better)...
With 75' of 3/4" (1/2psi) and the 5/8" tubing above (1/4psi), along with some losses for fittings (1/4-1/2 psi), diffuser losses (1/2 - 1 psi), and at 10' deep (5psi)...you get about 6.5 - 7.25 psi back pressure. The 0523 will be putting out about 4 CFM at this presure. This is good for 3 OR 4 diffusers at 10 foot deep.
Edit: Pay attention to your fittings and manifold ports. You want the inner diameter of these items to be close to the ID of the lines they are feeding. Otherwise, they create restrictions that add to your back pressure. For example, The bore in a 3/4-inch full bore ball valve is 3/4-inch in diameter. The bore in a 3/4-inch size standard bore ball valve is 1/2-inch.