You mention a lot of parameters. Would all of those be measured every hour? They all require different types of probes, and then usually come with as seperate logging solution. I have very limited HOBO experience, the main thing I hear they are cheap. Keep in mind that cheap is a different thing than 'value for money'.

The parameters that will be an issue in my experience: pH, nitrates, phosphates. Those parameters require regular calibration, and are sensitive to changes in the medium. I suggest to contact a good local installer with experience.

Please let us know what you decided and what your experience turned out to be!

Thank you Michel yes I agree cheap is not the same as value for money. I have also been looking at multimeter (TPSv90FL_MV meter) with different probes for each perimeter, YSI compact data sonde for unattended monitoring and the Eureka Manta multiparameter in situe logger. I have been using some Schlumberger micro divers for depth, temp and conductivity  but they are a bit expensive and those which i have on loan will need to be returned eventually. I will be logging hourly temp, conductivity, salinity, light and pH to capture daily changes and trends. Some of my sites are inaccessible in the northern wet season which means that I am messing quite a lot of data during this time. Thank you again for the advice I will let you know which I chose and how they are going in the field.

Leigh,

I agree with Michel, quality rather than price.

I have been using DataTaker data loggers for 8 years and can vouch for their quality and reliability. Being remote look at the power needs closely. The DT80's can handle the parameters you are wishing to record and i believe they have a new model that would be worth looking at DT85M. 

• Integrated cellular modem

• Ultra low-power design

• Automatic data transfer to email or FTP

• 1 Serial ‘Smart Sensor’ port

• Up to 15 Analog (± 30V) sensor inputs

• Expandable to 300 analog inputs

• 12 Flexible Digital channels

• Modbus for sensors and SCADA connection

• SDI-12 (multiple networks)

PS after sales advice, education and help is excellent.

Good luck

Cheers

Paul

I have deployed Hobo temperature loggers in dry river waterholes and to also measure ambient air temperatures with good success.  I first ran a detailed QAQC of the loggers and very high precision in the loggers.  I still use these same loggers in current research programs measuring water temperature conditions in marine and freshwater situations.

Thanks, Nathan

Leigh,  as Michel said, many of the parameters you want to start measuring (pH, salinity, DO, TDS, turbidity, nitrate, phosphate) can be measured with probes but these probes require frequent calibration.  In a wetland, I would say every 2 or 3 days.  A type of datalogger not mentioned above are those sold by Campbell Scientific.  They have a really nice webpage and make excellent dataloggers and sell all types of probes and ancillary instruments (radios, etc.), and can help you with connections to sensors they do not sell.  Also, you should consider that from a temporal standpoint, not all parameters are the same.  Temperature and rainfall require a higher frequency of monitoring than phosphates and TDS.  With this in mind, we have used probes connected to a datalogger directly (rain gauges, temperature probes, flow sensors, pressure transducers), and an automatic sampler (ISCO) also connected to the same datalogger, that can collect water samples so that other parameters (phosphate, nitrate, hormones, pesticides) can be monitored with greater accuracy, but less frequently.  You can even use the data from the probes to initiate sample collection.  See some of our papers on this:

Gall, Heather E., Chad T. Jafvert, and Byron Jenkinson, “Implementation of Hydrograph Modeling to Generate Storm-Specific Water Sampling Regimes”, Journal of Hydrology, 393:331-340, 2010.

Gall, Heather E., Stephen A. Sassman, Byron Jenkinson, Linda S. Lee, and Chad T. Jafvert, “Comparison of Export Dynamics of Nutrients and Animal-Borne Estrogens from a Tile-Drained Midwestern Agroecosystem”, Water Research, DOI: 10.1016/j.watres.2014.08.041, in press and available online, 2014.

Thank you Paul, Nathan and Chad your comments have been very helpful.  I will have a look at the loggers you have suggested and compare with the Hobo's and prob / multimeter options available. I have had a quick look at Campbell Scientific they have some good option. It may be that I will need to use a combination to sample at appropriate intervals for each perimeter. I understand for these perimeters regular calibration is necessary to maintain accuracy and will need to factor this into my sampling design. Thanks for the journal ref Chad I will have a look at these today.  Thanks again I appreciate the help Leigh. 

I've used HOBO products for monitoring hourly water/air temperatures on a remote Olympic Peninsula stream. This involved use of on-site thermographs and pocket thermometers (for spot-checking of thermograph accuracy). The thermographs were installed inside black-painted PVC piping and attached to nearby wood via steel cables for such surface loggers.

-Bob Vadas, Jr., WDFW-Habitat

Thanks Robert I use a similar method for installing my micro divers only I use white PVC.  

We use them here for temperature only, fixed on an aluminium stick with holes to reach different depths in the sediment. They are efficient and easy to use.

We have used HOBO Pendant dataloggers to measure air/water temperature in the Everglades wetlands for several years, left in the marsh unattended, sometimes covered with water and periphyton. The battery in these subtropical conditions lasts for about 9-10 months. They cost about US $30 each and are dependable. 

Leigh, the darkening of PVC pipe with eco-friendly paint provides camouflage, albeit it can rub off in later years via stream-bed scour. I used hourly thermal monitoring.

We have used hobo and Solinst dataloggers in Tuxpan, Veracruz, Mexico for 4 years; in mangroves and swamps with excellent results, they are a bit expensive but dependable. The data processing requieres some expertise and barometric data in order to compensate

Thank Eduardo, Anne, Zaki and everyone for the help I do appreciate your contributions.

Have a great day

Leigh

I have never personally used one but my Environmental Fluid Mechanics and Water Resource Engineering Lab at the University of Wisconsin has been using them on a regular basis for many years.

Thanks Nathan they do seem to be an cost effective tool.