So your digging the Tunze style of pump but don’t want to put out the cost? Get a “mod” which is very common do to among maxi jet style pumps. You can pick up this Maxi-Jet mod for about $19.99 online or perhaps locally at your local fish store. Features include: Works with 400 and 600 Maxi-JetÂ® pumps, Increases water flow (stream) over normal output, Anti Reverse-Flow Technology, Simple and easy attachment fully assembled. It is patent pending so we don’t really suggest copying it to resale. Although its been done before.