Two-Part Supplement Price Comparison

In all honesty, I hope that someone proves me horribly wrong with this thread. Most people that I have come to know in the reefkeeping hobby are incredibly honest, generous, and helpful. The big business aspect of reef aquariums is hardly realized by most, and is only really observed in the behavior of LFS employees. I have recently started dosing 2-part, and decided to compare prices of calcium, alkalinity, and magnesium supplements from different manufacturers and suppliers in order to get the best deal. The shocking numbers that emerged from this initially simple comparison were shocking, and must be shared. In this discussion, I will examine calcium, carbonate, and magnesium supplements prices on two levels:

1) Generic vs. Brand
2) Dry Supplement vs. Liquid Supplement

These comparisons are often difficult because the suppliers do not report the contents of their supplements on equal levels. This consequently puzzles those consumers without an adequate science or math background, thus tricking them into blindly overpaying for the advertised product. For example, dry supplements are often reported by weight, but are not always composed of 100% supplement. Furthermore, concentrations of liquid supplements are reported using several different units (i.e. ppm, meq/L, dKH, etc.) and are therefore difficult to compare to other brands, let alone dry supplements. Thus, I have converted all of the compared supplements to the same unit, that everyone can understand: price/pound.

I highly encourage anyone with any background in chemistry, biology, math, etc. to check my calculations because I probably made an error somewhere down the line (nobody’s perfect). Additionally, I urge anyone else to check prices, reported concentrations, etc. in case I made typo somewhere. For simplicity, I have deleted a few irrelevant columns that were only used for calculation purposes. Though, I have included the excel spreadsheet with all columns and calculations.







My conclusions (summarized in the table below):
1) On average, calcium, alkalinity, and magnesium liquid supplements cost approximately 7, 20, and 9 times as much as solid forms respectively.
2) Moreover, brand name calcium, alkalinity, and magnesium supplements are unbelievably over priced, costing about 215, 16, and 37 times as much as their generic counterparts respectively.
3) When comparing solid generic supplements to brand name liquid supplements, the brand name liquid calcium, alkalinity, and magnesium supplements are 291, 26, and 64 times as costly.
4) There was no instance of a generic/dry supplement costing more than a brand name/ liquid supplement within any particular chemical category.



Prior to this discussion, I am sure that it was known that dry supplements are cheaper in the long run, and that generic (non-aquarium) brands are cheaper than brand names, but I have never seen someone actually quantify it. The numbers are absolutely shocking. The only reason that I can think of that someone would buy a liquid supplement is because there are simple instructions on the side of the bottle that “seem” to require zero thought. In all actuality, this is probably the worst path you could choose because when a problem occurs, as it likely will, then you don’t really know what you did or how to fix it, thus requiring more thought (not to mention stress) then would have been required if it was done right the first time. It goes without saying that if you don’t really know enough about something, then you probably shouldn’t be doing it… I do not intend to sound mean with the previous statements, as I still have much to learn about the reefkeeping hobby myself. However, sometimes the truth hurts (and I do mean that quite literally) ;D.

 

Great work. I buy my baking soda from a Cash and Carry store and pay $6.69 for 10lbs.

 

I personaly buy the alk,cal,mag two part pre bagged to make a gallon at a time. From BRS ..

This works for me for numerous reasons including ease of making a gallon at a time.

Also I spend very little a year on this maybe 30 or so and I would say next too feeding my tank this is the second cheapest thing I toss money at IMO..

If I had a house I'd buy bulk and make it myself.

 

Ps great work ! And I'm sure this will help a lot of people out.

 

that is good work Gabby, thank you for sharing

one aspect, that I do not see covered is "what is the difference in terms of delivery capacity of the media chosen

if product A is twice as expensive as product B on a weight for weight basis
yet product A delivers ,more ( the supplement is more concentrated?)
that would offset some of the cost difference

although as you correctly point out, there will never be a parity between bottled liquid supplements and bulk dry supplements

people with nano reef set ups, are probably not using much in the way of additives, thus the bulk options will not offer the kind of savings that they would for larger set ups
IME the instructions on the liquid supplements such as Seachem,Brightwell and Kents are pretty accurate in their indications of what a given amount can contribute into a given volume,which is very helpful for those people who are building up their experience of dosing
they may or may not, later decide to take a more economical route , size of set up is often the trigger here

Steve

 

The shipping is very dependent on the person. For example, I am a paid Amazon Prime member and get free two-day shipping on most of the items that I order. I finally found a 10 lb aliquot of Mag Flake on ebay with $11 shipping, which is comparable to several retailers, including BRS.

On the other hand, the shipping costs for the 50 lb bag of dowflake that I found outweigh the cost of the material itself.. But after plugging it into the calculator, I found that it still beats the prices of all competitors, regardless of shipping. I also thought about where I would have the room to store 50 pounds of calcium chloride (probably next to the huge pile of salt and stuff in my hallway closet ). I posted a thread on my local reef club forum, and found numerous people who would split the cost of these bulk items with me!

I know that it would take some people a lifetime to use all of this material.. Though, I see people all the time with a list of items they use, but haven't the slightest clue why. I remember seeing a thread fairly recently where the best reason the OP gave for using whatever chemical it was because it provided amino acids. They didn't even know what an amino acid was, or why it was beneficial. After having to memorize the structure and properties of every amino acid in biochemistry, this just irritated me. Anyway, this thread wasn't meant to tell people what to buy or how to run their tanks, it was more to share my own research rather than just letting it sit on my hard drive. Sorry if I got on a little rant there!

 

No worries Gabby

but I am generally interested on knowing the delivery capacity of the products in question
as that is also connected with the economics

if product A delivers 2000 ppm calcium for 5 bucks and product B delivers 4000 ppm calcium for 17 bucks
then product B would not be 3 times as expensive as product A

on a weight to weight ratio it may appear so

by checking out the products on the www and working out costs should you purchase them, you have only told part of the story

bang for buck is the other part of the story?
do you have the figures on that apect?

Steve

 

If you look at the attached PDF's, the concentrations and purities are given (as available). These values were used to convert all supplements/brands to a common unit: price/pounds. For example, I compared Brightwell Aquatics Magnesion-P (dry supplement) and Kent Tech M (liquid supplement).

Brightwell Aquatics Magnesion-P
Concentration given as: 43% or 430,000 ppm magnesium
Example Aliquot: 300 grams
Price for 300 grams: $8.49
Calculation:
43% multiplied by the total weight of the supplement gives 129 grams. 129 grams is equal to 0.284 lbs. The price/lb Mg value was calculated by simply dividing the price ($8.49) by the number of pounds provided (0.284 lbs) yielding:
$29.85/lb magnesium

Kent Tech M:
Concentration given as: 70,000 ppm magnesium
Example Amount: 1,900 mL (64 fl. oz)
Price for 1,900 mL: $16.49
First, the concentration given as 70,000 ppm was converted to mg/L (70,000 ppm = 70,000 mg/L). This value was divided by 1000 to convert the unit to g/L (70,000 mg/L = 70 g/L). This value was multiplied by the volume of solution to obtain the weight of the actual dry product that is actually dissolved in the solution itself (70 g/L x 1.9 L = 133 g. Converting grams to pounds, 133 grams = 0.284 lbs. The price/lb Mg was calculated as before ($16.49/0.284 lbs Mg), yielding:
$56.24/lb Mg

Thus, the dry supplement Brightwell Aquatics Magnesion-P ($29.85/lb mg) is more economical than is the liquid supplement Kent Tech M ($56.24/lb Mg) when compared on equal levels. In other words, you will get more bang for your buck by choosing Brightwell Aquatics Magnesion-P over Kent Tech M.

I hope this answers your question. If not, can you please clarify? If there is something more I am missing, I would be happy to gather some more information and make some more figures to complete the rest of the story!

Steve, this has also sparked some additional questions in my mind about the purity of the generic and BRS calcium, carbonate, and magnesium solid supplements. I have contacted BRS, and will contact some of the other manufactures to obtain these values. I will update the tables and let you know when they get back to me…

 

Brilliant, thank you Gabby

I could not download the PDFs on my laptop today so missed the information they contained
I will check them out on my desk top computer at home later

Steve