Dissovled oxygen -> Looking for a meter to measure it or testing method.

[halemart]

Well, I am in search of an meter to measure oxygen in the tank.    Does anyone out there have one of these meters, and can they recommend one?     I have been looking at them on Amazon.com but I don't see any reviews on them.

 

They seem to be in the $200 - $500    range, I am wondering how long does the meter last?     I am just trying to get an idea of what to look for from those who have more experience than me.

 

 

Thanks.

[Rik Kretzinger]

I use the American Marine DO meter.  I run it continuously with a power supply. It is easy to calibrate and give consistent results.  Probes last about 9 months - they are the biggest part of the cost of the unit.  I have looked at other probes to purchase, but they are just as expensive.  Until you can start to buy wholesale the price will not drop much.

 

[halemart]

Thank you!

 

[halemart]

I know have this meter,   Starting to read thru the manual and trying to get this thing calibrated.     Too late tonight to do this but not sure about the electrolyte solution.

 

Next questions I have,   What is the normal range for fish for dissolved oxygen?     Where do I get replacement tips for this?

 

New world to explore.

[halemart]

Read the manual, and assembled oxygen meter,  then calibrated.

These are the results I got 

Indoor aquarium 3.9   20 gallon tank

Outdoor fish tank    6.1  Over 200 gallon tank.

 

Now to make sense of these readings.    I did a google search and someone was in the opinion that Talipa are better off with 4.0 for DO,   they said higher than that it was more than they really needed.     I am surprised at the readings myself, I was thinking it would be the other way around.     I think I will take a visit to my local lake and see what the DO level in the lake is.

[RupertofOZ]

Don't forget... your DO level will be influnced by water temperate... and even elevation..

[halemart]

Thanks Rupert, ya I have been reading other forum threads on DO, found this chart. 

 

http://www.aquatext.com/tables/oxygen.htm

 

which explains why fish like to be in cooler water.

[Rik Kretzinger]

As to your questions:

 

Calibration is a little tricky at first as you need to fill the cap with solution to calibrate and moving the switches back and forth.

 

As for caps do a google search on the following and you will have lots of options for them:

As for reading - once calibrated you just watch it and see what you get.  This time of year I can go as high as 20, night time temps are around 45F in a 100 gallon tank.  I run 24hours with two beds with E&F - 5 mins to fill and about 10 to drain.  With day time temps in the 60's I will run readings around 12-14.  In summer day time temp can get upto around 90F my DO will be down around 7-8. At night time I will see readings around 10-11.   I once hit 4 and started losing shubunkin's, in this case my electric shut off and I lost my cycle effect and the backup air pump.

[halemart]

Ok, after I calibrate do I leave the electrolyte in?      So, caps each last about 9 months then replacement cost is about 20$  not as bad as I thought, I thought one would have to replace the probe after 9 months.

[Rik Kretzinger]

I remove the electrolyte and rinse with distilled H2O a couple of times. Then I fill with tank water and install.  I do not know what they use in the electrolyte solution.  I have a rule that I never put anything into my tank without knowing if it will harm the fish.  If there is a question I always have a backup tank with goldfish that I can test before going in to my good tanks.  As for the caps I have never replaced them and I get good readings for about 9 months.  When my reading start to get weird readings such as a reading of 6 when the temp is cold and I have lots of water exchanges. I will recalibrate and if does not fix the problem and I am around the 9 month time frame I change out the probe.  After a little while you will have a good feel for what your reading should be and the reading for me just confirm that I am good on DO.  Your fish will also give you a good indication of DO levels.  As you start to gain an insight as to your readings make sure you watch the fish so you observe their behavior at the different levels and how they are acting.  Soon you will get very good at just looking at the fish and know if you have a problem.  Sometimes meters mess-up and for me they are just a gauge and a tool to understand my tank environment better.

[halemart]

Ok, I am not sure I have been calibrating this meter right, so I thought I would do a video of the steps that I have done for using this meter.

http://www.youtube.com/watch?v=M4IwC1VD1P4
http://www.youtube.com/watch?v=k_TNbmLOQt4

I think I got it down, but still would like another set of eyes so I know I am doing this right.

Thanks for your input Rik, I will send this to the company to see if they can verify if I am doing this right.

Mart

[Rik Kretzinger]

Mart -  you left out the last step in the calibration process.  Once you get to the 20.9 reading you need to move the DO switch from CAL to DO.  Then put it in your tank.  Doing it the way you are doing it you are still in the calibration mode, so you are in constant calibration and nothing will be held at the constant calibration point this way.  Once you move the switch back to DO mode your are ready for the tank and you will get correct readings.  As for the fluid, the pinpoint people are going to tell you to leave it in.  Which is ok, I have have found that over time the solution comes out and is replaced by tank water anyway.  Once you start to see the correlation between your water temp and aeration of the tank you can go with tank water and see if you experience any difference in reading.  I did not, but for your own piece of mind you should follow the manufactures instructions from the get-go.

Hope this helps,

rik

[halemart]

Thanks Rik.    Good to know I am on track, just need to set the switch..