LaMotte sells test kits for less than $50 if you want to go less expensive.
What Bob said. Guys do some of you really really need a D.O. meter? I raise fish in four ponds and hardly ever use mine. Used to use it when hauling fish (which I absolutely hate doing), but now if the aerator is running and I don't overload the tank there is no point in checking. If the aerator goes out is the D.O. meter going to make a difference? Heck no! If oxygen production stops there is no point in getting a reading! That's why I have oxygen back up if the aerator fails. Or some folks use oxygen and use the aerator as back up, or use both.
Same goes for a pond. If you have an impending fish kill and know the signs of an impending fish kill you'll know you going to have problems before the D.O. actually gets in the serious zone. (Algae bloom crashing and turning brown, Clarity due to an algae bloom less than 12 inches, odor in the water, fish off feed etc.) And if you have a fish kill your D.O. meter isn't going help you.
If you are a good pond manager, don't overload your ponds as in fish production ponds vs. recreational ponds, mix your water column with a diffuser in the summer you should never have to worry about a fish kill due to a turn over or low D.O, or have to take D.O. measurements. And for those of you in the north if you keep some water open during ice up or keep snow of then again you shouldn't have to worry about low D.O. then either. Yes there are exceptions but 99 percent of the time fish kills are the pond owner's fault and are completely preventable. Ignorance has killed a lot of fish. Been there done that.
For the amount of money you pay for a good meter you could spend just a little more and buy a LaMotte test and a surface aerator for an emergency! I paid over $700.00 for one and I can honestly tell you if I had to do it over I would just go with the LaMotte test Bob suggests. (I actually have a LaMotte test to calibrate the meter!) I actually trust the LaMotte test over the D.O. meter! This winter I doubled checked my D.O. with my LaMotte test just to be sure I wasn't getting a weird reading.
And here's another thing to keep in mind: I have a PHD in aquaculture down the road from me that raises thousands of dollars worth of hybrid striped bass in an recirculating aquaculture system. Guess what? He only uses the LaMotte or Hach test kits to keep track of water quality parameters. Says he doesn't trust meters. Apparently he's had a bad experience with one.
Look I know there are good reasons to have a meter (such as quicker readings of the water column without the need for a water capture system), but isn't it true in some cases we think we need a pricey gadget when we don't need it? You know, "The difference between men and boys is the toys for men are more expensive."
This is my two cents. Take it or leave it.
