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Thailandia Sunset
- Thread starter Hanuman
- Start date
Hi all,
cheers Darrel
I'm not sure, there almost certainly is a list somewhere, @Oldguy may know? We do have a thread with some discussion of the <"purity of calcium chloride"> (CaCl2.nH2O), where @X3NiTH may have answered this question?
cheers Darrel
MichaelJ
Member
Just add up the ionic charge. It won’t match the TDS as that will only match the calibration fluid but it will be darn close.
Cheers,
Michael
John q
Member
This is where we start to learn.
What's the difference between ppm and ionic charge.
1g of caso4 in 100ml of water assuming it dissolves, which it won't... should give us a total ppm of 4190 ish. Can this be back tracked to tds, are tds and ppm linked?
What's the difference between ppm and ionic charge.
1g of caso4 in 100ml of water assuming it dissolves, which it won't... should give us a total ppm of 4190 ish. Can this be back tracked to tds, are tds and ppm linked?
MichaelJ
Member
You can certainly calculate the electric conductivity (uS/cm) of a dissolved compound from the ionic conductivity and molar mass and then derive the TDS. Whether you will measure the same ppm depends on the TDS meter (conversion factor) and what dissolved compounds you’re measuring - it will only be an approximaiton. The ppm’s of the fertilizer and mineralization I’m mixing for my WC fairly well matches what I measure with my TDS meter - it’s about ~20 ppm’s off (as far as I remember) from just adding up all the ppms from the rotala calculator.
Cheers,
Michael
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When myself and @Hanuman added TDS reading to the IFC calculator based on the amount salt being added to a certain volume and the relevant maths. Hanni did some bench tests with various salts and we found the results compared to the TDS meter reading very acceptable, so we was happy to add the feature. Obviously all the salt has to dissolve, but Hanni did some solid work on the conditional formatting in Excel so it has 'bells and whistles' to let you know you have exceeded solubility limits for all the various salts
Hi all,
Also the actual TDS figure didn't matter to me. If the two products were exactly the same in purity I would have read the same TDS or very close (if you account for measuring errors with the scale and water volume) regardless of the number shown on screen. That's what I was after. Not the actual number.
Yes I was well aware that 1 gr of CaSO4 would not dissolve entirely in 100ml of water. That was exactly the point so that the solution would be totally saturated and I could compare how much sediment would be left out between the 2 solutions 🙂. There wasn't much if any difference at the end of the day. This was a way for me to assess if I was dealing with the same compounds or not, albeit not very precisely.
Also the actual TDS figure didn't matter to me. If the two products were exactly the same in purity I would have read the same TDS or very close (if you account for measuring errors with the scale and water volume) regardless of the number shown on screen. That's what I was after. Not the actual number.
Indeed. I mean, we did make the IFC calculator and looked at 100s of compounds solubility limits in multiple conditions from multiple sources and multiple times after all 😅.
I have to say I have no clue about this. Try to make it as precise as possible. I used a 0.1 precision scale and a 100 ml lab graduated cylinder.
Let's see what our trusty @X3NiTH has to say on the subject. Would be interesting to know why there was such a difference in tds readings between the two. I assumed that one was contaminated/less pure than the other but I could be wrong.
Oldguy
Member
With reference to some of the above posts, just don't go there. You will be entrapped by the Nernst equation. This hobby is for enjoyment not flagellation.
The solubilities of chemicals can be found on the internet.
Common ions will reduce solubility ie Ca & Mg Carbonates, the carbonates will 'add up' to precipitate Ca & Mg below their individual solubilities, so use dilute solutions and add larger volumes to you tanks. (Even non common ions can reduce total soublities [I once had a fad of making transition metal complexes in a range of colours and some were sods to get out of solution, so used various very soluble salts to form saturated solutions to try and 'force' the desired compound out of solution]).
To a first approximation ppm and TDS can be viewed as the same thing.
Do not take as gospel your test kit and meter readings they are a useful guide. The real test: are plants and critters doing well.
Enjoy the hobby, have fun and I wish you all a Happy New Year.
The solubilities of chemicals can be found on the internet.
Common ions will reduce solubility ie Ca & Mg Carbonates, the carbonates will 'add up' to precipitate Ca & Mg below their individual solubilities, so use dilute solutions and add larger volumes to you tanks. (Even non common ions can reduce total soublities [I once had a fad of making transition metal complexes in a range of colours and some were sods to get out of solution, so used various very soluble salts to form saturated solutions to try and 'force' the desired compound out of solution]).
To a first approximation ppm and TDS can be viewed as the same thing.
Do not take as gospel your test kit and meter readings they are a useful guide. The real test: are plants and critters doing well.
Enjoy the hobby, have fun and I wish you all a Happy New Year.
I'm considering adding some urea to my ferts schedule, but my idea was to keep it separated from the main mix so that I can front load as usual and then add urea 3 times a week. Any reason not to go this way? Maybe I could even mix urea and micros, since I don't front load them...
John q
Member
Urea is only available for a short period, the chemists will explain why,. I dose small amounts mixed in with my micros.. it seems to work.
Give this thread a read if one is considering crossing to the dark side.
Dosing with Ammonia and Urea
Decided to open a new thread on this very interesting subject rather than carry it on in the Good Algae Article thread - http://ukaps.org/forum/viewtopic.php?t=905 Here's what been said so far: As George alluded to, some vendors use ammonia salts as their source of N, which I find completely...
www.ukaps.org
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With urea that's the best move. Dose little more often. That is why I moved from front loading to 3x a week but I think it's best to spread it even more. Interestingly it never occurred to me I could mix the urea with the micro hence why I added it to the macros. It made more sense at the time.
This 3x dosing thing I am not liking so far so I might just add some urea to my micro, redo my macro bottle and go back to front loading like I was a few weeks back.
This is true. Also, the purity indeed does matter to some people and people should keep an eye on the Grade when purchasing any Chemical.
This is definitely the case but I live in country where not everything is always clear to the consumer. In the USA and Europe there are probably legislations in place that makes things easier and safer for the consumer. I used to buy the CaSO4*2H2O in a chemistry supply shop because it's the only one that would properly label the hydrate, problem is there was no grade mentioned (it's probably laboratory or technical grade). Everywhere else it was just CaSO4 and the origin was suspicious with no grade mention. Here they like to repackage stuff with home made labels, so you understand my suspicions. Anyway, I was recently able to find a shop that sold food grade CaSO4 and in principle that's CaSO4*2H2O. I can notice a clear physical difference between the two products. The food grade stuff is really a very fine powder that doesn't clump which is not the case with the other product. When I add the new product in my skimmer everything will dissolved and will be expelled within a few minutes. With the former product I always had some clumps remain for a day or two. I am also noticing more exoskeletons in the tank which mean shrimps are molting properly.
Also, regarding grades, one cannot always find high quality grades here unless you pay a fortune for some specific compounds.
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MichaelJ
Member
Yes. Food grade do not necessarily imply purity. As far as the FDA goes here in the US, It only means it's safe for human consumption which includes whatever impurities might be in the compound - impurities that potentially could be hazardous to our livestock. If you want to be more sure - and break the bank - you need ACS grade compounds.
Cheers,
Michael
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I bought the CaSO4 in a chem supply shop for education, so meant for schools and experimentation. I assume that was technical or lab grade, perhaps even lowers, who knows. If you read the link above posted by @Happi, Laboratory grade is actually not even pure enough for food consumption. So not sure what is what but I do see an improvement in shrimps so it must be better than what I had before.
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MichaelJ
Member
right on... I meant ACS grade.... but even that with its > 95% purity might still cause issues for sensitive critters.... we just cant know.
MichaelJ
Member
Dang! That's some pricy CaSO4.
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No it's all good. However I can't acess that website. I get this:
Can you please post a screenshot? I guess the website doesn't like me being in Thailand.
