Remineralizing RO Water

[tam]

I just wanted to add in that I've used them too, as much as it might have saved a few pounds... but not a lot as a smallish tank and low water change % so not going through it. It's just feels easier over having to mix from a few containers... source from suppliers in bigger quantities, worry if you're doing it right etc.

It's good there are cheaper alternatives but don't feel bad if buying a tub takes away something that would add a hassle for you and therefore makes your hobby more enjoyable. Some people love that aspect of DIY, others don't. There are lots of ways to save money from waiting longer for plants to grow in to spawning your own fish. Just pick what priorities work for you.

 

[MichaelJ]

It's fairly well acknowledged that is exactly what they are. In fact I believe it has been noted that given how easily they dissolve, they are the most likely the slightly less desirable Chloride based variants (MgCl2 and/or CaCl2). They may add a little KCl too, but the 'trace elements' will largely be impurities in the main salts.

Totally agree @Wookii . As a matter of fact if you want to keep TDS as low as possible for a given GH (E.g. if you keep shrimps 😉 ) you want to use CaSO4 (Gypsum salt) / MgSO4 (Epsom Salt) or just cut it with plain tap if its otherwise good and mainly CaCO3. If not, and if TDS is of no concern, or you want to pre-batch your Calcium/Mg (GH) solution, CaCl2/MgSO4 is what you want to use due to its much higher solubility. If you use CaCl2 just make sure it's not exposed to air when stored as it is highly hygroscopic (sucks up moisture from the air). As far as the additional "minerals" in Salty Shrimp and Shrimp King GH; whatever they "add" (if not just impurities as @Wookii said) in addition to Ca and Mg is of no significance to the shrimps. Whatever additional minerals the shrimps need they will get from their food.

Just in general; be careful when referring to TDS ppm's and remineralization - you have to actually measure the GH or better, KNOW what quantities your adding to the water in terms of Ca and Mg to establish the correct GH. Also a TDS measurement depends on the conversion factor from EC to ppm used by the TDS meter - EC in uS/cm which our TDS meters are actually measuring - the factor will typically be anything from 0.5, 0.64 or 0.7. The TDS ppm's you get from a solution will not really match the actual ppm - only a gravimetric analysis can establish the true ppm of an evaporated solution (or you can calculate it if you know the molar mass etc. of the compounds you are using). I have probably written well over a hundred posts on the topic on UKAPS over the years - I wish I had Darrels (@dw1305) skills to sprinkle my post with references and links to some of the better ones 🙂

Cheers,
Michael

 

[Iain Sutherland]

I wish I had Darrels (@dw1305) skills to sprinkle my post with references and links

He is the link Master of the Universe! 🤓

 

[hamfist]

Just in general; be careful when referring to TDS ppm's and remineralization - you have to actually measure the GH or better, KNOW what quantities your adding to the water in terms of Ca and Mg to establish the correct GH. Also a TDS measurement depends on the conversion factor from EC to ppm used by the TDS meter - EC in uS/cm which our TDS meters are actually measuring - the factor will typically be anything from 0.5, 0.64 or 0.7. The TDS ppm's you get from a solution will not really match the actual ppm - only a gravimetric analysis can establish the true ppm of an evaporated solution (or you can calculate it if you know the molar mass etc. of the compounds you are using). I have probably written well over a hundred posts on the topic on UKAPS over the years - I wish I had Darrels (@dw1305) skills to sprinkle my post with references and links to some of the better ones 🙂

Yes, completely agree.
However, for simplicity and ease of making up new water, once one has mixed up your first batch of SS GH+ in RO and actually got the GH to where you want it to be, according to a good GH test (this is the step I failed to mention in my initial post), you can then measure the TDS. Thereafter, if you use the same TDS pen each time, all you need to do with further batches is add SS GH+ to get that same TDS, and you will know that the GH is right. It just so happens that my TDS pen seems to correlate pretty well with the correct 17.9 ppm per degree GH conversion (ie. it measures roughly an extra 18 ppm for each extra degree of GH of the GH+ remineraliser I add (according to the API liquid GH test).

 

[dw1305]

Hi all,

Its such a shame that companies such as Salty Shrimp (with Seachem being probably the worst offender) use secrecy as a deliberate marketing tool.

They do, their aim is to <"obscure the truth"> using conjecture and some very carefully worded blurb.

I would love to know the genuine, and not just the alleged, composition of course

I will bet that it will be some combination of cheap and <"easily available compounds">.

Once you are past the design of the container you buy them in, there isn't any issue of <"aesthetics with fertilisers etc">. Ions don't "know" which compound they originated from. As an example every calcium (Ca++) ion on Earth has been combined in a multitude of different compounds during the ~7 billion years since they formed in the nuclear furnace of an imploding massive Yellow Giant star - <"NOIRLab: Astronomers Sink Their Teeth Into Special Supernova - AURA Astronomy">.

And do the company actually even know what those trace elements are or are they simply mainly contaminants ?........ I would also love to know the composition of the almost (alleged) 0.5% trace elements in SS GH+

You can get <"analytical grade chemicals">, with a high degree of purity, but they are very expensive. For a lot of chemicals there is any value in refining them any further than is required, so they have a certain degree of impurity left from their manufacturing process.

This is <"Calcium chloride - Wikipedia">

In much of the world, calcium chloride is derived from limestone as a by-product of the Solvay process, ...... In the US, most calcium chloride is obtained by purification from brine. As with most bulk commodity salt products, trace amounts of other cations from the alkali metals and alkaline earth metals (groups 1 and 2) and other anions from the halogens (group 17) typically occur.

cheers Darrel

 

[dw1305]

Hi all,

Just in general; be careful when referring to TDS ppm's and remineralization - you have to actually measure the GH or better, KNOW what quantities your adding to the water in terms of Ca and Mg to establish the correct GH.

I usually assume (the basis for these assumptions is in <"Guide to TDS">):

• That you get 1 : 1 dGH : dKH (from dissolved limestone (CaCO3)) in UK tap water, and
• that the dGH is overwhelmingly from calcium (Ca++) ions, and
• that conductivity and Ca++ and 2HCO3- ions are (approximately) positively correlated.

But these are all assumptions and ones that may not hold true for other areas, away from the S. of the UK.

Whilst dGH and dKH are linked using <"hard water as your remineraliser">, you can <"decouple them"> with your own designer mix.

cheers Darrel

 

[dw1305]

Hi all,
@hamfist you should be able to get tap water hardness figures from your water company -<"Home - Southern Water">, but it will be about 17- 18 dGH & 17 - 18 dKH <"for geological reasons">.

Our water (above) (just E. of Bath) is from a limestone aquifer <"and pretty consistent through the year">, if you have some surface water it will be a bit more variable.

However, for simplicity and ease of making up new water, once one has mixed up your first batch of SS GH+ in RO and actually got the GH to where you want it to be, according to a good GH test (this is the step I failed to mention in my initial post), you can then measure the TDS.

If you didn't want to use your tap water as a remineralising agent? Rather than relying on the GH test strips I'd go the other way around and make a standard solution and then test that with the strips. If you wanted a quick and dirty calibration? You could just use your tap water, or buy some mineral water of known chemical composition - <"French Click - Badoit Verte 6x1L">. I used to do this for work, and just wander around a few supermarkets until I'd bought "spring water" with a range of mineral contents.

The derivations and formulae you need are in Larry Frank's <"The Krib"> article linked here: <"Confusion concerning 0dKH and nitrification">

You could add calcium chloride (CaCl2.2H2O) and magnesium sulphate (MgSO4.7H2O) to RO water to give you a standard solution of known dGH. They are both salts that are cheap to buy (£5 / kg) for culinary, or health, reasons.

cheers Darrel

 

[Rich Jackson]

I’d use magnesium sulphate and calcium sulphate. 3:1 ratio of Ca:Mg, and raise to a GH of 6.

Where are you getting these from ?

 

[hypnogogia]

Where are you getting these from ?

I think I got mine from APC Pure, but you'll probably find them on eBay as well.