Has anyone ever used Oxygen meters such as Temperature Plus Oxygen Meter from Cabelas? This device claims to show the DO from 0 to 16 ppm. If so I would like to know your experiences with this or any other DO finding device.

Thanks a bunch

I've used electronic water testing gadgets for a lot of years as part of my career, but don't know how well the ones offered there work. I'm used to machines costing $700 or much more. I'd guess the one you are looking at is accurate enough for eliminating dead water, but there are tow things needed for total satisfaction. Make sure the unit comes with a long lead that can sample water at a useful depth other than at the surface. Surface water will almost always have high oxygen content compared to deeper water. Pocket tersters with a 4" probe is fine for shallow creeks.

A second issue is sensor replacement. The parts that sample oxygen, pH, and other water qualities tend to deteriorate long before the unit corrodes. I wouldn't buy a unit that doesn't have replacement sensors. It won't hurt to stock up on a few extras in case support for the unit ends.

A good unit that would really help study a lake is a combo DO/pH meter with 25 foot cord and replaceable sensor head. If you'll indicate how much you are willing to spend maybe I can steer you to something. However, I've learned you can get the information you need just by observing depth of baitfish and determining depth & thickness of a thermocline. I simply fish at or above those. The only useful information I can think of concerning DO is potential activity of suspended bass. pH (acidity) helps determine whether fish are able to utilize DO efficiently or not.

Jim

Jim,

Thank you very much for your response. That was exactly what I was looking for. For a long time I have used my graph to find the thermocline and targeted fish at those lvls. I had always thought that just at or slightly above the thermocline held the best and most fish. I was just unable to find any documentation that stated that the very best O2 at that same lvl. I have looked at several report on the Oxygen Levels at local lakes for this month. I have graphed the Thermocline and the best lvls from the report pretty much match the thermocline. I guess to make it short. Would you think that on suppended fish that the DO is better where they are even though the thermocline is more than likely below them?? Or do you think that suppended fish are usually part of a double thermocline event??

Thanks for your response.

Oxygen enters lake water two ways. One is from surface mixing...boat props, wind, direct absorption, etc.  A second source is from submerged vegetation, oxygen entering and rising. Over thick vegetation DO could be nearly consistently saturated to the surface. But over a non-vegetated bottom DO tends to decrease with depth. A thermocline is mostly a matter to temperature ("thermo"), simply a contact zone separating warmer (epilimnion) upper lake water from colder deeper (hypolimnion) water. The thermocline shows up on sonar because colder water is denser, and the temperature change takes place rapidly in only a few feet of depth. Water temperature affects capacity to hold DO. Warmer water molecules are farther apart, able to allow O2 to slip between them. Bass require more DO than many other species, so must find a comfortable balance usually above the thermocline to find enough DO, yet deep enough to cool down. It's rare they will suspend below a thermocline, even though a preferred water temperature is there. They can chase forage deeper, but not remain in water generally below 5 PPM (parts per million) of DO unless they have no alternative. At that concentration they begin to shut down, varying depending on water temperature. Feeding usually stops at around 6 PPM. They can suspend and rest, digest a meal there, then move up into better DO to have energy to feed again. They can be at their best around 8 PPM and higher. Each fishery and even section of one fishery is different, a little change in pH alone changing reactions to DO changes.

Hope that answers.

Jim

YES. That answered my question spot on. That was good stuff Jim I really appreciate it. And on top of all that I believe exactly what you said