Comparisons between Agricultural grade and Reagent ACS grade chemicals

[Maven]

Recently a doctor who takes care of his own large planted tank in his office made a post asking about the grade of the ferts Greg Watson sells. Greg Watson posted and said he buys agricultural grade chemicals in bulk. The doctor said he was uncomfortable with the fact that the impurities in the agricultural grades are unknown, as are their levels. Probably fine for agriculture, but he had rare fish and plants and wanted a better grade.

Most everyone attacked him, saying he was bashing Greg Watson and that he was an idiot for even thinking this mattered. The conversation wasn't even allowed to continue and the thread was locked.

I think it's a sad state of our hobby when new ideas get attacked without hesitation. I think it's a sad state of our hobby when certain people's words get taken as gospel without even an ounce of skepticism or questioning. Some of these certain people are even downright rude in character (I think you know who I mean).

I for one wanted to try ACS (American Chemical Society) grade chemicals for myself just to compare the difference in the agricultural chemicals I already have on hand from gregwatson.com.

It was suggested that the "end customer" can't order ACS grade chemicals as they are regulated by Homeland Security and the DEA. I found out that this isn't true. Many large lab suppliers won't sell chemicals to the end customer, but there are those who do and they aren't breaking any laws. I found one and ordered some reagent ACS Grade K2SO4, CaCl2*2H2O, and MgSO4*7H2O.

Here are some of the differences I noted:

• With the Greg Watson chemicals, the formulas that were discussed and posted on the boards never quite yielded the expected results. For example, Hypancistrus, KevinC, and some other people got into computing dosages based on atomic weights. I think it was Hypancistrus who concluded that 79.39 milligrams of CaCl2*2H2O and 33.27 milligrams of MgSO4*7H2O will raise GH in 1 gallon of water by 1 dGH while maintaining a 4:1 ca:mg ratio. When actually doing this, my test results never quite matched this. For example, when dosing my tank at a water change (I use RO/DI water), I would compute dosages for raising GH. I target 6 dGH. But when I test after adding, I found that sometimes I would need to add 80%, sometimes 60%, or sometimes more, like 120% or 140%, to obtain my targeted dGH.
  
  With the ACS chemicals, I found that the dGH increase EXACTLY matched the computations. I calculate and measure for 6 dGH, and the test results return 6 dGH. So far it's been consistent with 3 water changes.
  
  This does lead me to question the purity of agricultural CaCl2 and MgSO4.
  
  
  
• One thing I immediately noticed is that I didn't even have to stir to get the ACS chemicals to dissolve. I bought a stirrer after reading about them on the boards. When I measured the CaCl2 for example, poured in some water, and brought it to the stirrer, I found that I could see no solid pieces in the container. Just pouring in water was enough to get it to dissolve completely. I am not sure if this means anything significant, it is just a difference I am pointing out.
  
  
  
• Finally, a picture comparison. This is K2SO4. These pictures were resized and sharpened a bit, but the color is unretouched. All pics were taken under the same lighting in the same position.
  
  
  
  Greg Watson agricultural grade K2SO4:
  
  
  
  
  
  
  
  Reagent ACS grade K2SO4:
  
  
  
  
  
  
  
  Greg Watson agricultural grade K2SO4 - 1 teaspoon in 200 mL RO/DI water, on stirrer for 10 minutes:
  
  
  
  
  
  (The stir bar in the bottom is magnetic. The black specs on the stir bar must be a type of magnetized metal. The other stuff on the bottom is unknown matter which doesn't dissolve.)
  
  
  
  Reagent ACS grade K2SO4 - 1 teaspoon in 200 mL RO/DI water, on stirrer for 10 minutes:
  
  
  
  

I would like to emphasize that I am NOT "bashing" Greg Watson. I have never talked to him but from what I understand, he is a hobbyist like the rest of us and he's very nice. He says right on his site "these are for agriculture," he's not misrepresenting what he is selling in any way. The only thing he's doing that I think will eventually get him into trouble is he's shipping Potassium Nitrate via the US mail, which is a BIG no-no. He may just not realize the folly in doing this if he gets caught. He needs to switch to a carrier like UPS for this and he has to designate the package as a hazardous material (oxidizer). It's not me, that's just the rules. I don't like them either!

For me personally, I don't view my hobby as "growing weeds." I go nuts over the rare stuff and I don't mind paying extra to get it. That's part of the fun for me. This goes for plants and fish. One argument is "the unknown impurities are just trace elements so what's the problem." The doctor said it best, it's that the impurities are unknown and so are their levels. From what I have discovered above, I believe the levels of impurities in these agricultural chemicals is not as insignificant as believed. With reagent ACS chemicals, I can control the trace elements because I can remineralize my water with highly pure salts, then add a trace mix (I use Flourish) where the "impurities" and their levels ARE known and have been "tweaked" for planted aquariums. So, I have decided I am most comfortable with these reagent ACS chemicals.

I doubt the Doctor will visit the boards again after the extreme negative response he received, but if by chance he is reading, I'd like to thank him.

If you do a little searching on the net, you can get Reagent ACS chemicals for lower prices. Yes, they are more expensive than Greg Watson. Many people think a product is evil if it is more expensive. But then again many people love Amano and his products are probably some of the most expensive in the industry. Again for me personally, I don't mind paying a bit more. I initially bought small quantities, but they can be found for $30 - $40 per 5 pounds (which as most of you know will last a LONG time).

[Hypancistrus]

I've always wondered what all that crap is in the K2SO4.

Aren't stirrers great?

I also get the inconsistancies with the GH, I end up only needing to add about 60% of what I calculate, otherwise I overshoot. Maybe it's the extra water... perhaps the CaCl2 from Greg Watson is actually anhydrous... or perhaps it's a mix of anhydrous and dihydrous. Just a guess?

Can you say where you got your Reagent ACS chemicals? I'd like to try them.

[Maven]

Try:

clarksonlab.com
chemsavers.com

Or even eBay.

[Hypancistrus]

I'll e-mail Clarkson Lab, that's where I got my Lamotte Potassium Test Kit.

Thanks!

[plantbrain]

I do not think the issue is such that the grade provides better growth or not, but rather an issue of more accurate measurements.
I have high grade stuff and use it forn some things when needed.

But it's not needed for growing plants in this hobby........."weeds" or not.
I also do not need a 3000$ test monitor to do this hobby, but I want to know some things and do research.

If you desire to do research that's fine, but for him to suggest that research grade ferts are needed is a stretch to say the least.

You can pay more for the increased purity, whether it's really meaningful or not in terms of plant health/growth is quite another matter.

You may also consider using RO/DI triple treated water, purchasing nice testing equipment.

But do you need it?
Will it make a difference in terms of the plants?

No.

That's my point here on this issue. Please show otherwise.

You say there are differences, I do not disagree with that and would suggest that sounds about right. I done testing and quickly concluded it did not matter, our tolerances are simply not that precise in this hobby, nor need to be.

My question is far more practical, is there a significant difference bewteen these products in our case? Do the impurities cause issues?

Having used both of them, I cannot say so.
Steve and I used research grade stuff years ago.
Doesn't do any better/worse than with greg's stuff.

I hear a great deal of talk over research grade stuff here, yet few/none do any research on aquatic weeds.

The way the issue was presented was such that there is a serious problem with our ferts that folks have successfully been using for close 15 years without issue.

I challenge that assertion as it is not true my, nor most other's observations with plants over decade time frames and 300 species of plants.

Nothing wrong with paying more, if you feel better, more power to you, it's your $ and that's the trade off, the trade off is not with the plants health/growth themselves.

Show me otherwise in terms of aquatic horticulture..................
I use the good stuff for research, I use plain old cheap stuff for the yard, the tank, field..........

Regards,
Tom Barr

3rd annual Plant Fest July 8-14th 2005!
subscribe@BarrReport.com Get connected
www.BarrReport.com Get the information

[Buck]

Originally Posted by Maven

For me personally, I don't view my hobby as "growing weeds." I go nuts over the rare stuff

I hate to tell you this but even the "rare" stuff is a weed somewhere in the world and if you asked that plant what the purity percentages were in the ferts you are using , even the "rare" plants would still shrug a stem and say ... I dont care.
Good lighting, CO2 and the presence of enough of all the micro's and macro's to maintain growth and health without an excess to feed algae will grow an AGA Champion Tank.
I am not knocking you for your desire for purity but I do not understand what you think a "rare" plant has in its properties that requires that level of purity ?
If anything in the tank would not appreciate impurities in the ferts it will be your fish LONG before the plants.
BTW... what are you growing for rare varieties ? I would love to see some photos of your plants Maven.
Thanks for the comparisons and photos... very interesting.

[Momotaro]

I am going to let this stand ...for know, but if this goes the way of the last thread on the subject it is gone!

Most everyone attacked him, saying he was bashing Greg Watson and that he was an idiot for even thinking this mattered. The conversation wasn't even allowed to continue and the thread was locked.

I am going to comment on that, Maven, only because the last thread on this subject really bothered me.

The good "Doctor" went to two separate forums and posted the same thing on those sites, VERBATIM. Even his subsequent posts and counter arguments on those threads were exactly the same, VERBATIM. Kind of like this thread here and the exact same thread you started over at the other site. More than one member on this site and the other site was skeptical of the "Doctor". Granted, Planted Tank was tough on the "Doctor", but the other site wasn't at all, yet his responses and claims of persecution were exactly the same on both forums. That really made some people wonder. In my opinion, the "Doctor" was little more than a troll. The conversation was locked on this site and the other because neither this site or the other is going to indulge a troll. Don't wag you finger at us!

I think it's a sad state of our hobby when new ideas get attacked without hesitation. I think it's a sad state of our hobby when certain people's words get taken as gospel without even an ounce of skepticism or questioning. Some of these certain people are even downright rude in character (I think you know who I mean).

That is a sad thing. It is also a sad thing when someone refuses to accept the years of experience this and other hobbyists have had with certain products.

It is a very sad thing when someone comes to a forum and comments on a person's character or their perception of that person's character without any real knowledge of that person. Again, don't wag your finger.

If you want to comment on the condition of the fertilizers we have been using within the hobby, then go right ahead Maven. You are more than welcome to do that. However, if your intention is to come here and comment on the temper and demeanor of this forum or it's members, than you can bet this thread will be locked.

Mike

[Rex Grigg]

I went though about 150 lbs of K2SO4 a couple of years ago. Many of you may have gotten some of it.

I noticed nothing of the sort of black dots in the whole batch. In fact I can just drop it in the water and it dissolves. Nothing left. Just water with K2SO4 in it.

[Pearljam11]

There are just way to many things alot more important to worry about in regards to keeping my aquariums and fish, to put much thought into such issues, in my opinion.

[Lionel]

I would love to know specifically what kind and amounts of impurities are in "agricultural grade" as opposed to reagent grade.

I keep discus, and also have kept saltwater/reef tanks. in salt, you dont want to add anything that might adversely affect the inhabitants of your tank. if there was a posibility of adding some unknown element by dosing a supplement, I would not do it. what I mean is, i wouldnt knowingly add an unknown or potentialy unstable thing to a closed system.

JMO..

[awrieger]

How they make K2SO4.

They basically dig it out of the ground. From a mine. Like coal. They don't make it in a lab, where they add things to it. Most of it is processed at the mine site where it's sent straight as a finished product to wholesalers for repackaging and never even sees the inside of a pristine laboratory.

Actually they use hot brine water to dissolve veins of it, then pump the solution up to the surface. Where they dehydrate it again, and voila, pure K2SO4 crystals just like they make table salt. Sulphate and nitrate crystalise at different temps, so basically the result should be pure K2SO4 and nothing else. Any impurities would come from the mine equipment, or the dirty industrial surroundings, eg dust, grime, bird poop, unclean packing equipment etc after it's already been crystallised.

If you look at the bottom pic on the right, you can see this particular mine's screeners (to separate crystal sizes into grades) are rusty. This probably explains the small bits of metal in Maven's sample. Most likely rust.

'ACS grade' I would assume is crystallised instead in a sterile, controlled environment to prevent contamination. A third party probably buys the mine's product and performs the process again in cleaner conditions.

Paragraph to note in the link supplied:

A fine grade of potash - approximately -48/+ 1 00 mesh - is used mainly for liquid fertilizer applications. Standard grades of potash for both industrial and agricultural applications are approximately -20/+65-mesh. Coarse grades of -6/+14 mesh and granular of -5/+12 mesh are used in the blending grades of fertilizers.

So grades aren't based on quality, but crystal size. The smallest crystal size is the best and used in liquid fertilisers. I assume because the smaller ones dissolve better? I have no idea how that works sorry.

'Agricultural grade' is actually one step down (in crystal size) from 'liquid fertiliser grade'. Which is what we would want, isn't it? Liquid fertiliser grade of K2SO4?

Hope that helps.

[Maven]

Originally Posted by plantbrain

The way the issue was presented was such that there is a serious problem with our ferts that folks have successfully been using for close 15 years without issue.

This to me is a flaw in your thinking. How can you possibly know this... so much so that you know that "folks have used 15 years without issue." You are actually saying you have first hand knowledge of all people who have planted tanks, use agricultural grade chemicals, and none of them have any problems or issues?

I see countless posts on all the plant boards that follow the lines of "My water parameters are all in check, all my levels are good and have not changed, but all of a sudden, I have X or Y or Z or some combination of problems." What's not to say that one, two, a few, or more of these issues just might be caused by impurities? For example, high silicates in a certain batch of a certain chemical that were progressively added to a tank over time and lead to a diatom outbreak?

Science is best guess, but a big folly I often see on these boards is "My water parameters are all in check but I have holes in one of my plants," followed by, "You have a potassium deficiency." That's not best guess, that's wild guess!

You clearly project that your mindset is the type that looks at the planted tank as a weed farm. As I mentioned, I don't share this angle of viewing the hobby. Have you ever seen some of the plants we keep in tanks in the wild? For example, Madagascar Lace growing in its native habitat is nowhere near as pretty, well developed, intact, and colorful as it is in a tank with the highest quality water possible at all times. This is the same case for many other (notice I didn't say all other) species. In the wild, they do look like weeds!

Some of us strive for excellent water quality and the best looking specimens possible. Frankly, after all the blood, sweat, and tears I put into it, I find it rather insulting.

Originally Posted by Rex Grigg

I noticed nothing of the sort of black dots in the whole batch. In fact I can just drop it in the water and it dissolves. Nothing left. Just water with K2SO4 in it.

Again a very good example of what I view as a problem... impurities and their levels vary from batch to batch. Place an order for K2SO4 from Greg Watson, if he still has the same batch he had when I ordered, you will see I am not making this up.

Originally Posted by Momotaro

The good "Doctor" went to two separate forums and posted the same thing on those sites, VERBATIM... In my opinion, the "Doctor" was little more than a troll.

Well, I see many duplicate posts on different forums all the time from obviously the same user, I've always interpreted it as the user is just trying to get his question more exposure. Personally, I think they were a lot harder on him over at APC. I saw him as someone who raised a question about personal concerns and got intimidated. His subject matter was quite on topic I think, and it lead to me following his advice. So I am following the advice of a troll!

I'm sorry you see me as "wagging my finger" at you. On-topic debates and discussions should be allowed, even if the ideas are controversial. Despite heated tempers and disagreements, new information is eventually discovered. This is historically how progress is made in any area of science, government, or any other aspect of civilized society!

[SCMurphy]

Unfortunately all you are doing is yelling "FIRE" in a crowded theater, something that is not a first amendment right, not that we are obligated in a private international forum to adhere to that amendment, but we do our best. The Good Doctor did that as well, yelled "fire" with his very first post, and he never responded to any of the polite and helpful responses he got, which were mixed in with the 'other stuff' which we had to chastise people about. We really don't mind cross posting questions, but if your only posts on a forum are to yell "fire", and you cross post them, you don't look like you have a desire for discussion.

You know if you knock off the first three paragraphs of your original post, and some of the proselytizing the in second half, you have a good post which would generate a great deal of useful discussion. People respond differently to factual information and ranting. If you had taken your analysis a step further and reported to us what the contaminates are that you identified that we should be worrying about, and what levels they are found in the sample you have, and what levels would be bad in an aquarium, you'd be supplying real information. Other then that, all you have is conjecture and arm waving, yelling "fire".

Oh, when someone has pinholes in a plant, K deficiency is a very good possibility, and it has happened to enough people that the repeated affliction/correction has moved it out of the realm of pure conjecture. Since it is one of the easiest things to correct for without harming the balance of the rest of the tank, after K is proven yea or nay we can move on to the next possibility which might not be so easy to detect or correct for. I'd find a better example.

My recommendation is that you step back, take a moment, and think about the point of your topic. If it is to generate discussion, then supply the information and leave the personal rants out of it.

[Hypancistrus]

Originally Posted by SCMurphy

If you had taken your analysis a step further and reported to us what the contaminates are that you identified that we should be worrying about, and what levels they are found in the sample you have, and what levels would be bad in an aquarium, you'd be supplying real information.

How is he supposed to identify the impurities? Not everyone has a gas chromatograph in their house. He said his concern is unknown impurities.

I apologize for taking the side of the underdog here, but I don't see anyone yelling "fire!" He just says he was upset that the original threads were locked, he investigated a bit further, and posted what he found, taking the time to take pictures even. I have no problem with him.

Originally Posted by Maven

On-topic debates and discussions should be allowed, even if the ideas are controversial. Despite heated tempers and disagreements, new information is eventually discovered. This is historically how progress is made in any area of science, government, or any other aspect of civilized society!

I couldn't agree more.

Originally Posted by Rex Grigg

I noticed nothing of the sort of black dots in the whole batch.

He is definitely not making it up... I bought some K2SO4 from Greg Watson and that is exactly what mine looks like.

I never really was comfortable in fact dumping this:



...into my tank.

I almost feel dirty buying these "controversial" () Reagent ACS grade chemicals now.

[SCMurphy]

You missed the point. No one is disputing his pictures, only the presentation.