Testing Devices - Colorimeter?

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Gerryd

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Sep 23, 2007
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Hi Tom,

I want to get some facts about my tank, instead of guessing all/most the time.....

So, this question should be near and dear to your heart lol

What type of test equipment would you recommend with a total budget of $500-700?

I have a nice Hanna PH/temp monitor/meter (running 24/7) and I have an Apogee PAR meter with the remote sensor arriving next week :)

Can I even touch a decent colorimeter for this range? Would one even be worth the expense? I know that they range in the number of things that they can test, based on the $.

What would you recommend as minimal tests that the meter/device should perform?

Or should I really save my money and maybe just get the c02 in-situ meter?
Assuming I am doing EI and 50% WC so I at least can get a decent idea of N and P in my tank based on my dosing.

I also know they have smaller meters for Iron, BOD, o2, etc. Would any of these be worth the expense?

The PH meter has been great to help with adjusting my c02 and the venturi.
I expect the PAR meter will also help answer some of my questions about my light setup.

My MH are now 17" above the water surface, and I still get 6" of L. inclinata va cuba growth over 5 days. And this is in the end of the tank that gets the LEAST light... Can't wait to see what I get at various points in the tank........

Thanks in advance.
 
Tom Barr

Tom Barr

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Well, the colorimeter aint bad, so yes, you can get them in this range, ebay, Hach are very good, look for the 800 series, 890 is the best.

Otherwise, the single parameter test from Hanna are decent, 170-190 each for NH4/NO3/PO4/K+.

Fe is all that's left and that's a problem even with colormieters.
The other metals are not nearly as bad.

The cost is really the reagents..........not an issue if you can make them yourself, but few aquarist can or have the facilities, know enough about chemistry, are willing to stock a lot of it. So the Test kit places make a good $$$ from this.

In the long run, this is where to cost are.

I'm more inclined to give advice about the Hach 800 series or the Hanna single parameters, they make a C200 or something that does several parameters that's a bit more user friendly than the Hach.

You7 should be able to use most semi accurate colorimeter/spects for any known wavelength lamba peak for any test method, but you need to know the lamba, this is typically available etc. Standard Methords in Drinking and Wastewater is an excellent reference and you simply ask Hach or buy, download the various methods they have and set a cheaper Spect at that wavelength and run their(or your own DIY) reagents.

This is typically a good deal if............. you plan on running 200 test at a time, high replications, many subsamples etc.

Aquarist are notorious for not using high reps, typical they use a replication of 1:mad:

You cannot say much about that.....but many try.

Here's a few tricks to get around that to data that's meaningful(a rep of one is not meaningful).

1. Run blocks, repeat the same test of the tank while trying to maintain things constant. Then add these up. The blocks will take longer, but the trade off is that you do not have 20 tanks all the same. This method works best for aquariums but takes a lot longer to get decent replications and there's the issue of keeping things constant while you run the test. But the plant species, fish, flow , trimming, light etc can be maintained much easier.

2. Need a reference tank for a control. So you need enough control to do things right in the first place. Only then, can you manipulate and test a hypothesis- a priori.

3. Freeze your water samples(say 20 mls- enough for 4 reps typically), per day, week etc and then test all at once, then look at and analyze the data.
Most aquarist look at testing for monitoring purposes, which is fine, you may do that and this since you can freeze them and test later in a large big batch to see longer term trends, perhaps your test methods where not consistent over the total time period etc.

4. Take smaller time frame sampling(less issues can get in the way), but the trade off there is that you lose resolution, perhaps the method used for testing is unable to detect smaller ppm differences. So you might need longer time frames between sampling.

Regards,
Tom Barr
 
G

Gerryd

Plant Guru Team
Lifetime Member
Sep 23, 2007
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