I have been learning heaps from you guys, but there are some basic principles about pumps and filtering that I just don't understand.
My pond is shallow (30cms, local regulations), and random shaped, but most closely resembles an hourglass where the two wide bits are around 2 metres across. I have two pumps - one is a fountain style that just shoots water up into the air and let's it fall back decoratively. It has a large (housebrick size)block of foam style prefilter. That prefilter clogs up with algae in a couple of days, and I hose it off with the same rainwater that is used when I top up the pond. The other pump takes water from the pond and recycles it up to a waterfall, via a commercial filter with UV light.
The commercial filter isn't very good, it has a backwash for cleaning, but dirty water never comes out when we try it. We haven't been able to pull it apart to change filter material, and are not sure we could do so without causing damage. So it will be replaced or we will add in an extra filter. I have looked at the homemade filters here, and the principle seems fine, and I think I could make one of those.
Here is where I get confused. I assume I need a pump in the pond with it's own little (or not so little) prefilter to send the water up to the filter proper. The bit I don't understand is how this setup would be any more effective than the simple little fountain pump with it's big prefilter. The pond has lots of string algae and floating algae, which I manually remove almost daily. There is also plant debris such as spent Azolla and pond flowers and leaves, fish poop, and of course the bits of plant material and insects that get blown into the pond. Some of this stuff gets drawn onto my current prefilter and I clean it frequently. Some of it just floats around and some of it sinks. The water that comes out of the fountain prefilter has very few bits left, as evidenced by the fountain clogging only occasionally. But the amounts of gunk in he pond are increasing.
How would a new filter be any better at dealing with the large volumes of algae and plant material? The way I am thinking, the water getting to the new filter would be pretty clean anyway by the time it got through the prefilter. If I didn't have a prefilter, the pump would die pretty quickly from the string algae, and there would be a risk of fishies getting sucked up.
Can someone please help me understand this?
My pond is shallow (30cms, local regulations), and random shaped, but most closely resembles an hourglass where the two wide bits are around 2 metres across. I have two pumps - one is a fountain style that just shoots water up into the air and let's it fall back decoratively. It has a large (housebrick size)block of foam style prefilter. That prefilter clogs up with algae in a couple of days, and I hose it off with the same rainwater that is used when I top up the pond. The other pump takes water from the pond and recycles it up to a waterfall, via a commercial filter with UV light.
The commercial filter isn't very good, it has a backwash for cleaning, but dirty water never comes out when we try it. We haven't been able to pull it apart to change filter material, and are not sure we could do so without causing damage. So it will be replaced or we will add in an extra filter. I have looked at the homemade filters here, and the principle seems fine, and I think I could make one of those.
Here is where I get confused. I assume I need a pump in the pond with it's own little (or not so little) prefilter to send the water up to the filter proper. The bit I don't understand is how this setup would be any more effective than the simple little fountain pump with it's big prefilter. The pond has lots of string algae and floating algae, which I manually remove almost daily. There is also plant debris such as spent Azolla and pond flowers and leaves, fish poop, and of course the bits of plant material and insects that get blown into the pond. Some of this stuff gets drawn onto my current prefilter and I clean it frequently. Some of it just floats around and some of it sinks. The water that comes out of the fountain prefilter has very few bits left, as evidenced by the fountain clogging only occasionally. But the amounts of gunk in he pond are increasing.
How would a new filter be any better at dealing with the large volumes of algae and plant material? The way I am thinking, the water getting to the new filter would be pretty clean anyway by the time it got through the prefilter. If I didn't have a prefilter, the pump would die pretty quickly from the string algae, and there would be a risk of fishies getting sucked up.
Can someone please help me understand this?