This works good in my 55,
Took a 1 gal jug (Hanovers Plastic Pretzel Container,like a little Rigid keg) poked hole 1 inch down from the lip with a solder iron (Round approx. 1/8 Rod tipped one)
I asked a Doctor Buddy to get me an I.V. Drip tubing setup,no bag (from standard issue for a bag set up) cut off the bag conector(just use the tubing and flow adjustmnet slider) and stuck it trough the hole and down to a depth off 1 inch above bottom inside container,super glue in place when your done at the end (weighted end down with rubber band and chunk of old live rock rubble,Hell glue it in there above sediment line, inch or so).
Put slider flow adjuster couple inches from the top on the outside(were you can get at it) dangle remaining end down to hieght you need to the tank in need (leave little extra til your sure) secure this end in a way you can undo it if your taking jug to mix some where else(I glued a clip to tank rim). Keep in mind jug has to be above tanks water level .
I think this would work well for the DYI guys with small tanks,
Oh yeah. get one of the small butter tubs that fit perfectly in the top openning it will sit half way down in.Great place to coil up tube when moving to mix area also seals air movemnt from the jug alowing for enough to get by for very steady drip rate.
ScottbytheSea