Had a 25 gallon Fimco.  Ended up replacing the pump with one like this https://www.amazon.com/SHURFLO-8000-543-238-Shurflo-Pump/dp/B0020IRI28/ref=sr_1_4?gclid=Cj0KCQjwvdXpBRCoARIsAMJSKqKZJm_VwXhBFmYQJPfu-t5HWRDc_XddIELnI0KrNtow9f-GMuatHKoaApOEEALw_wcB&hvadid=241892823966&hvdev=c&hvlocphy=9022293&hvnetw=g&hvpos=1t1&hvqmt=b&hvrand=14240790870255148862&hvtargid=aud-676677759484%3Akwd-11536788838&hydadcr=24634_10399776&keywords=shurflo+100+psi+pump&qid=1563845052&s=gateway&sr=8-4  Much better pump with a lot more spray distance.

Also have a 50 gallon homemade sprayer mounted to a pallet.  Has a 4 roller hypro pump a regulator and a predator engine on it with a spray gun like this https://www.amazon.com/Hudson-38505-Ges-HeavyDuty-Spray/dp/B0040C6YHW/ref=sr_1_43?gclid=Cj0KCQjwvdXpBRCoARIsAMJSKqJdMDsrCcQCJ7eh52uGolyMgSC8AxGLJGUC1CWgJr6aIyuNuf-o0xQaAqmvEALw_wcB&hvadid=241635992871&hvdev=c&hvlocphy=9022293&hvnetw=g&hvpos=1t1&hvqmt=e&hvrand=11887974687314482256&hvtargid=aud-676677759484%3Akwd-12625412&hydadcr=26614_9892225&keywords=spray+gun&qid=1563845261&s=gateway&sr=8-43  on it.  Can really fog some spray out with it to kill some brush.  Have another one just like it we put bug killer only in to spray yards, trees, and around houses with.  They just fit inside the gator bed, and can also be used in a pickup.