yme;34447 said:
I also bought the same co2 analyser without datalogger. just to expensive
I don't miss it either.
As for the measurements: for me it really takes a long time to give a stable readout >30 minutes. But I do measure everywhere more or less the same CO2 levels : 30-35 ppm. I do not see a gradient. Nor is it much lower in the plants.
btw: what are the calibration fluids? I got a little flask of it but that is now finished and it is almost time to recalibrate: tom, do you know??
yme
They should have calibrated it at the factory. I check it with the stirring chamber about once every 6 months or if I want to be careful and recheck things.
The long stabilization times are worrisome, I'd calibrate it.
5 min is plenty of time for most cases, you should calibrate.
You might try 40-45ppm range of CO2 and note the difference(assuming the 30-35ppm is good). Even at moderate lighting, I found this to be good, but much more than this, fish may suffer. This is for Discus, they tend to be much more sensntive to high CO2 than other fish and these are very large discus.
They are good for this due to larger size(larger fish are more sensitive-high O2 demand) and discus have a nice dark color change when stessed.
I'm a bit leary suggesting 40-45ppm to folks because their measurement and monitoring is often poor and the risk is high. However, with this meter, if it's calibrated, you should be able to safely add CO2.
They see what the real CO2 ppms are that infleunce fish etc.
A trick you can do to get instenaneous CO2 is to withdraw a sample of water in the region of interest in the aquarim. Then place it in a sealed chamber with the CO2 meter probe sealed in side. As long as the trasnfer prcoess and chamber are sealed and no CO2 is allowed to degas, then you can take all the time you want to get to CO2 reading.
Then you know what the CO2 when you withdrew the water at that location.
I think a flow through sampling chamber you can pull water through into the chamber is ideal for this.
See here:
http://www.rickly.com/wqi/images/FLOWCELL.JPG
http://www.ottoenvironmental.com/products/50216.jpg
And simply add a gas proof seal for the CO2 probe.
Regards,
Tom Barr