IffersTankSlave
C'mon SPRING!!
Any chance of a group buy on the Hach test kits demonstrated so ably by Greg Hiller at the past meeting? (Feb.26). Would be VERY interested.
Hach test kits? (Calcium + Magnesium)
- Thread starter IffersTankSlave
- Start date
Greg Hiller
BRS Moderator
The kit that you want is called 'Hardness, total and calcium'. It will do magnesium and calcium for you. Cat # 1457-01, 20-400 mg/l Model HA-4P mg/l
I will post later with more details about how to dilute the sample and calculate out the numbers. I also ran through some back of the envelope calculations and will post those later regarding the cost of the kit, etc. The site is HACH.com
I will post later with more details about how to dilute the sample and calculate out the numbers. I also ran through some back of the envelope calculations and will post those later regarding the cost of the kit, etc. The site is HACH.com
Thanks Greg. Ok, I'll coordinate the pooled order, but I would like payment from everyone before I order the kits (they aren't cheap!). Please post here if you are interested. In the meantime, I'll go on the site and figure out how much each kit costs with shipping. I'd like to be able to bring the kits to the next meeting, so I'll also figure out a drop deadline for ordering. More to come...stay posted.
Daire
Daire
Greg Hiller
BRS Moderator
You thought this would be easy didn't you!?!
Okay, here's some back of the envelope (actually I did it on a napkin!) calculations.
First, let me say that I have not used any hobbyist test kits in a long time, so they may be quite accurate now, I just don't know. Last time I used them I think it was the SeaChem kit and I was unimpressed with it. I think I also used the one by Rea Sea at one time and was even less impressed (reagent tended to leak out of the dropper bottles and evaporate, which would likely significantly affect the results).
What I can say is that I've been using the Hach test kit for quite some time now and am very pleased with the results.
Now to the numbers:
I've seen the Salifert calcium test kit go for ~$23. Supposedly it will do 100 tests, but that might depend upon the calcium level because you might go through more reagent if the calcium level is high (I don't really know because I haven't used the kit). Assuming no shipping costs that's about $0.23/test.
For magnesium I've seen the Salifert magnesium kit go for $24, it will do 50 tests but I believe that might depend upon the level of magnesium. This kit I have used, and was quite pleased with it, but I don't think I got 50 tests out of it. IF we assume 50 tests however we come up with $0.48/test.
THE HACH $ NUMBERS:
First of all, the kit costs $55 plus shipping. The kit will do both calcium and magnesium. It comes with 100 packets of the calcium reagent, so the max number of calcium tests is 100. If you dilute your sample as I recommend (I'll post more about that later), you will save yourself some of the titrating reagent (EDTA based) and if only used for calcium, the EDTA solution (100 ml) would be good for about 160 tests assuming calcium in your tank was about 420 ppm). You can purchase the calcium test packets from HACH directly to 'reload' your test kit, and the cost for the packets is about $0.12/packet (not including shipping, and you have to buy in pack of 100). The cost to 'reload' the EDTA solution is $10/100 ml.
The same HACH kit will also run magnesium. The 'consumables' on the magnesium test is really only the EDTA titrant solution (same solution as the calcium test), and once again, diluting your sample before you start will save a lot of the titrant. The way I have been diluting my sample will use ~1.7 ml of the titrant per test. If you were using the kit ONLY for magnesium then you would have enough reagent for ~58 tests. You could also dilute your sample further before doing the magnesium test and use less reagent.
The magnesium test kit also uses two other reagents from the kit, but they are used in such small concentrations that it would be hard to ever run out of them (in fact, if someone was even more of a cheap Bast#@$ than me you could probably split one HACH kit into several if you aliquoted the other reagents into extra stopper bottles).
So...the problem with all the numbers above is the limiting material is likely to be the EDTA titrant. I made some for myself a while back in the lab. I went back and priced out the cost of the chemicals I was using.
MORE ASSUMPTIONS:
Most people would likely be happy for a LONG time with enough reagent to do....let's say 200 tests of calcium and 200 of magnesium (you could test for each twice a month for 8.3 years!!). Using the test the way I do that would mean you would need a total of about 440 ml of the homemade EDTA titrant reagent as I have been making it up.
If we assume 30 people were interested that would be ~13 liters of reagent. I calculated that I would need $80 worth of propylene glycol and $32 worth of EDTA to prep the EDTA reagent for this many people. That works out to about $3.73/per person for the EDTA reagent. The question is how can I purchase the chemicals (as I'm a little reluctant to nab them from my lab)? The numbers I gave were direct from the Sigma chemical company catalog.
These are not particularly dangerous chemicals. From my old workplace (small company) I was able to just reimburse the company, but where I work now I really cannot do this.
Okay, here's some back of the envelope (actually I did it on a napkin!) calculations.
First, let me say that I have not used any hobbyist test kits in a long time, so they may be quite accurate now, I just don't know. Last time I used them I think it was the SeaChem kit and I was unimpressed with it. I think I also used the one by Rea Sea at one time and was even less impressed (reagent tended to leak out of the dropper bottles and evaporate, which would likely significantly affect the results).
What I can say is that I've been using the Hach test kit for quite some time now and am very pleased with the results.
Now to the numbers:
I've seen the Salifert calcium test kit go for ~$23. Supposedly it will do 100 tests, but that might depend upon the calcium level because you might go through more reagent if the calcium level is high (I don't really know because I haven't used the kit). Assuming no shipping costs that's about $0.23/test.
For magnesium I've seen the Salifert magnesium kit go for $24, it will do 50 tests but I believe that might depend upon the level of magnesium. This kit I have used, and was quite pleased with it, but I don't think I got 50 tests out of it. IF we assume 50 tests however we come up with $0.48/test.
THE HACH $ NUMBERS:
First of all, the kit costs $55 plus shipping. The kit will do both calcium and magnesium. It comes with 100 packets of the calcium reagent, so the max number of calcium tests is 100. If you dilute your sample as I recommend (I'll post more about that later), you will save yourself some of the titrating reagent (EDTA based) and if only used for calcium, the EDTA solution (100 ml) would be good for about 160 tests assuming calcium in your tank was about 420 ppm). You can purchase the calcium test packets from HACH directly to 'reload' your test kit, and the cost for the packets is about $0.12/packet (not including shipping, and you have to buy in pack of 100). The cost to 'reload' the EDTA solution is $10/100 ml.
The same HACH kit will also run magnesium. The 'consumables' on the magnesium test is really only the EDTA titrant solution (same solution as the calcium test), and once again, diluting your sample before you start will save a lot of the titrant. The way I have been diluting my sample will use ~1.7 ml of the titrant per test. If you were using the kit ONLY for magnesium then you would have enough reagent for ~58 tests. You could also dilute your sample further before doing the magnesium test and use less reagent.
The magnesium test kit also uses two other reagents from the kit, but they are used in such small concentrations that it would be hard to ever run out of them (in fact, if someone was even more of a cheap Bast#@$ than me you could probably split one HACH kit into several if you aliquoted the other reagents into extra stopper bottles).
So...the problem with all the numbers above is the limiting material is likely to be the EDTA titrant. I made some for myself a while back in the lab. I went back and priced out the cost of the chemicals I was using.
MORE ASSUMPTIONS:
Most people would likely be happy for a LONG time with enough reagent to do....let's say 200 tests of calcium and 200 of magnesium (you could test for each twice a month for 8.3 years!!). Using the test the way I do that would mean you would need a total of about 440 ml of the homemade EDTA titrant reagent as I have been making it up.
If we assume 30 people were interested that would be ~13 liters of reagent. I calculated that I would need $80 worth of propylene glycol and $32 worth of EDTA to prep the EDTA reagent for this many people. That works out to about $3.73/per person for the EDTA reagent. The question is how can I purchase the chemicals (as I'm a little reluctant to nab them from my lab)? The numbers I gave were direct from the Sigma chemical company catalog.
These are not particularly dangerous chemicals. From my old workplace (small company) I was able to just reimburse the company, but where I work now I really cannot do this.
Greg Hiller
BRS Moderator
>So are you asking if there is anyone out there who can get the necessary chemicals?<
Yup...that's my ultra long winded way of doing it!
Yup...that's my ultra long winded way of doing it!
OP
OP
IffersTankSlave
C'mon SPRING!!
I am in for one, too!
Shallowwaters
Non-member
What the heck. My Seachem is just about out and I don't trust Salifert after getting one bad test kit. Count me in!
If you guys still want me to order these, I'll need to get payment up front. Can you get me a check or paypal me by Wed of next week (the 23rd)? Then I'll submit the order by Thursday and hopefully have it for the meeting. If so, I'll PM you my address or paypal id - LMK. The total is $295.50 (55.50 per kit + 18 shipping) which is 59.10 each.
Last edited:
OP
OP
IffersTankSlave
C'mon SPRING!!
Daire, I can do Paypal. Let me know the ID, and I'll send it off to you. Thanks for the effort on this.
Greg Hiller
BRS Moderator
The date of the meeting is about 98% certain to be April 2nd, 10-2 PM in Billrica
