Simply Koi and More Koi

hi
does anyone know how many lph a central heating pump circulates please?
cheers

From memory the 3 speed models do roughly 900/600/300 gallons per hour on speeds 3/2/1. This is at zero head though, dont try using them to pump at a height.

heard somewhere that they are not suitable for koi / fish as they are made of brass and copper.

having said that i used one on a small goldfish pond for a couple of years- with no ill effects

Hi
yes I got 4 of these Grundfos pumps running my pond , there's no brass or copper in them but they are made of cast iron , some say this is not enough to be a problem but just to be on the safe side I coated the insides with G4 , been running for years with no problem , Bob's about right with the gallonage.

I had a couple of people I know who used them. The opened the pump and coated the inside with several layers of Hamerite.

Hi Scott
I thought of hamerite but did not know if was fish friendly so went for the G4 option.

they also do a conversion so the nasty bits are removed and a plastic housing and impellor are fitted....

That's right Vipp's its called the Aquaturn about £15 in most koi mags .
I would have considered these but their in or outlet is in a different place to the original if I remember correctly .

I be interested if any one knows what the larger 25 /60 shifts or if it only pumps to a greater head.

In fact I'm told there is a new low wattage pump called alpha am I correct , any plumbers out there