i know this is an old thread ,, BUT i have experience of these and they are exactly like all other powerheads a narrow jet of water , unless you add the fish tail which spreads the water a bit but the one i had kept coming off because of the force. so i super glued it on. then after 1 month it stopped turning side to side so i took it to bits to check and the wheel inner section some of the teeth had already worn down to almost nothing for some reason. and the metal shaft was rusting.
i complained but all emails were ignored.
but i love hydor powerheads there brill. and have some pretty nifty new larger powerheads available which may be ideal for those with large tanks.