A while ago I bought the MG Chemicals budget etchant kit.  The kit comes with a sparging unit, five liter tank, and air pump.  It was about $30, which sounded reasonable at the time.  Having tried using the tank a couple of times, I'm not smitten.  The board holder would probably work really well for a 9" board...but since I work with small, simple circuits...the holder (integrated into the sparging unit) is worthless.  I ended up drilling holes in my board to hang the board from.

That brings me to the sparging unit.  This thing is supposed to circulate the etchant in the tank, and around the board by bubbling air into the tank.  Right.  First, the tubing is really stiff (think fish tank tubing), so the sparging unit never wants to sit straight.  Also...all the air came out of only one end of the unit, so the distribution was not uniform.  Could I have fixed this?  Maybe...except the thing is submerged in a vat of acid.

Alright.  I was pretty irritated when my boards didn't turn out well, so I went to the store and bought a fish tank heater for $10.  Then I decided to get some more flexible tubing, and a stone aerator.  My first concern was that the acid would eat up the stone or the silicon tubing.  Not so, as it turns out!

So...here's the lowdown.  If you want to get an etching tank, don't buy the MG Chemicals kit.  Go buy a five liter Tupperware container with a seal able lid.  Buy a fish tank aerator, heater, air stone, and silicon tubing.  You'll spend only about $25, and get a heated tank out of the deal.  I purchased some rubber tongs which may work for holding small boards, but I may just stick with drilling holes and hanging them in the tank.