Help please!! Need help choosing filtration
Hi all I'm getting back I'm to the hobby and I'm stuck on which filter size to go for. I've got a 90 litre tank with (4) 2" koi and I'm looking at the "all pond solutions" range. They do a 450 l/h for tanks up to 90 ltr or a 600 l/h for tanks up to 110 ltr. Which do I think would be best??