I will try again. My first tome got wiped out, timed out.
With the additional info you added I think more info from you is needed.
-Size of main C.B. supplying the W.pump , filter setup, UV lgt.
-Size of main supply wire from C.B. to the equipment
-is the other equipment fused and the size of those fuses.
-size of the wire to the other equipment
-amp draw of the equipment
Industrially it is common and perfectly good to use a large C.B. and heavier wire, sized for the combined total load, for the bulk of the run untill close to the equipment and then use individual fuses or circuit breakers close to the point of use for individual pieces of equipment.
Most of the equipment I used to work on often brought in a large cable of 480-600V and hundreds of amps capacity into a breaker panel or machine control box. Then each sub piece of equipment , motors, heaters, controls, had their own smaller feeds protected by fuses or C.B.
You case is of course pushing the analogy a lot but it still works. Is there extra C.B. space at the panel as lack of space is often the driver for similar setups. The builder usually does not leave enough spare openings for additional breakers over the years.
In your case If the P.O. used a large C.B. and main supply wire, + & -, large enough to supply adequately and allow for voltage loss, the pieces of equipment you mentioned may be well served as they are, with smaller fuses/C.B. to protect the wiring and equipment beyond. Just be sure the above is paid attention to.
In this case the UV light and filters [?] are not of much use when the pump is out of commission since all work as a system yet each piece will be protected. Of course the sub connections should also be covered and the joins/connections done properly.
Check the fuse holders. Loose clips, springs or dirt/corrosion/oxidation will cause nuisance failures of fuses. The looseness/dirt will create unwarranted heat which will melt the fuse element from the fuse cap inside the fuse body. If the fuse blew from a true overload then usually the narrowed actual fuse section will fail.
If heat from looseness is the problem often the element will be intact but will separate from the cap. Often an ohmmeter is needed to check it.
Same is true for the blade type fuses, ATO.
The pump could also be blowing the fuses now due to the bearings getting tight from rust. Pumps have shaft seals and they can leak allowing water into the motor area causing the bearings to rust. That will cause increased current to be drawn blowing the fuse.
How is the pump oriented? Ideally the motor should be atop the pump. If the pump is atop or even horizontal to the motor, water will have a much easier time entering the motor when the seal fails.
The labouring sound and the gurgling may indicate a leak of water and air past the seal and water damaging the bearings.
It may be time to rebuild the pump including the bearings.
When removing the hoses, quickly raise the ends above the tank if possible and cap and tie them up.
I installed mini handle full flow 1/2" ball valves to close off the supply and output hoses. I also installed BRASS, good quality, threaded hose fittings to easily separate the pump for service. The fittings are installed reversed, supply to output, so the connections will not be easily reversed.
DO NOT USE PLASTIC HOSE FITTINGS. Some may be ok but if not they will blow and make a big mess and you could lose all the water if not caught quickly.
