R.O. Right does not read on test kit.

[DSenn]

This is a weird one. When I add R.O. Right to my R.O. water, it does not show up on the GH test kit whatsoever. It doesn't matter if I add a quarter teaspoon or if I add 4 teaspoons, it simply does not read. I know it is not my test kit, because I use it for testing my tap and it works fine. The funny thing is (which is related to my other thread about R.O. Right) is that when I add a ton of it, it gives me a pH! The more I add, the higher the pH, but with no reading as me having GH!!! Can someone please enlighten me here before I lose my marbles to this hobby.

 

[Purrbox]

Could you possibly have gotten a bad batch? Perhaps contact the manufacturer for more information.

 

[CaptainAhab]

to some extent you can verify by checking the TDS difference between the before and after sample. Gh tests usually only test for calc and mg missing the trace elements, potassium , salt etc...

 

[jsoong]

I don't know the exact composition of R/O right (some secret formula!). I would suspect that it is mostly NaHCO3.

At any rate, pH is related to the buffer - the anion (eg HCO3-, CO3--, PO4---, etc). The only one that we measure is HCO3 (KH).

The cation is not involved in the pH equation. The only cation you are measuring in GH is Ca & Mg. If R/O right contains mostly NaHCO3 (baking soda), you will not be able to measure how much you have added with the GH kit (since the cation is Na). You can only do that using the KH kit. <And that is not totally accurate, as I suspect R/O right has other buffers in addition to HCO3).

 

[OasisKeeper]

At any rate, pH is related to the buffer - the anion (eg HCO3-, CO3--, PO4---, etc). The only one that we measure is HCO3 (KH).

First off, Howdy!. Long time aquarium and reef keeper here although I have been away from the hobby for a fair number of years.

So, coming back to the hobby and hoping to get a handle on freshwater plants this go around, I have been trying to relearn all my water chemistry. So on to the point:

I believe most test kits work by acid titration and really cannot distinguish between anions although unless you have some really strange water, they are most likely overwhelmingly bicarbonates (HCO3) anyhoo.

You are really measuring alkalinity, which is fine, because that is what you really need to know anyway: i.e. how well you water can buffer against PH shifts due to co2 (carbonic acid) or organic acids from other sources.

The only reason I bother to mention this is because some of us (turns out to be me) have some pretty strange water. My tap water turns out to be salty with a Kh higher by a fair bit then the Gh.

Dilution with RO/DI always works, of coarse, but leaves my GH low when I get the Kh where I'd like it to be. I am still considering what and how much I want to do about this. Too be honest I almost certainly tend to be a little to concerned over such things. But hey, gives me something to worry over in my spare time.

I guess my final word on this for now would be, yeppers, water chemistry is not something you are likely to wrap you head around without a fair effort to study it. The good news it you don't really have to if you are not that interested in it and, on the other hand, you can sink a lot of time into it if it spins your wheels.

Good luck to all.

 

[DSenn]

OasisKeeper...it's funny you mention how mixing R.O. water with your tap leaves you with a low GH. I am the opposite, whereas when I mix my tap and R.O., I get very little KH!!! Please God, someone shoot me now. My current dilution has been a 2:1 ratio, 2 gallons R.O., 1 gallon tap. This seems to leave me with a nice 6.8-7 pH, 2-3 dGH, and a tiny 1 dKH. I think this is what I am going to stick with, at least for now. I know 1dKH is low, but I don't know what else to do to get my KH up higher without raising my pH. I guess by keeping up with the water changes I can replenish it on a regular basis, I don't know.

In terms of the R.O. Right, I say whatever. The chemistry you are throwing at me is beyond me for one (in terms of croutons and onions and R.O. Right does not contain baking soda, to my knowledge. As far as I know, R.O. Right is for GH only. If it doesn't show up on my test kit, then I say f*-K it, not using it. Mixing tap and R.O. is the only way I can have piece of mind that my fish are getting at least SOME hardness.

 

[DSenn]

P.S. Oasiskeeper...when you dilute, what numbers in terms of ph/KH/GH do you come up with, and what are your ratios?

 

[OasisKeeper]

DSenn, you remember the story of the blind man and the elephant? Well, in this case you are trying to make a certain kind of elephant by measuring and adjusting the trunk, the ears, and the tail.

Okay, not quite that bad, but you get the drift.

As I stated, I haven't really decided how I am going to deal with my water but can cover a few things.

First, dilution with RO/DI should give you linear reduction by ratio of both Gh and Kh. I.E. a 1:1 ratio will cut both Gh and Kh in half.

PH is another measurement and another matter. It changes based upon the reactions of ions in the water. Dilution may have little to no effect upon the PH.

I guess the bigger question is why worry. My water has nitrates, is salty, and has high alkalinity (kh) out of the tap, which is why I bother with it at all. Depending on the condition of your tap water, it may not be worth the trouble to change it at all.

 

[DSenn]

I'm more of a mad scientist at this point than a practical fish keeper. You're definitely right about the 1:1 ratio. My GH and KH are cut right in half. I guess what I am trying to understand is how people achieve a successful soft water aquarium, which obviously leads me to trying to understand how to alter my pH, which has led me to trying to understand how to alter my KH, which has led me to trying to REDUCE my KH. When I reduce my KH to 1 degree, my pH only gets as low as 6.8-7 (which is FINE, I know, I know) but now I have no KH. Is this bad? I've never had a pH crash before, but I've also never had a successful soft water aquarium and I don't want a pH crash. I guess the best way to get lower than this on my pH is to add CO2...

In your case, maybe you should strip your water to the point where you achieve the KH you want (which is what, if you don't mind me asking). Obviously you won't have any GH, but you can add this back using a buffer (like R.O. Right).

 

[OasisKeeper]

I'm more of a mad scientist at this point than a practical fish keeper. You're definitely right about the 1:1 ratio. My GH and KH are cut right in half. I guess what I am trying to understand is how people achieve a successful soft water aquarium, which obviously leads me to trying to understand how to alter my pH, which has led me to trying to understand how to alter my KH, which has led me to trying to REDUCE my KH.

Some folks have soft or at least balanced water to start with. The other route is to start with RO/DI and remineralize it (like RO Right). I take it that this is what you tried but didn't like the result. This is one of the issues with using these commercial products that don't actually tell you what you are adding to the water. When things don't work per the instructions, its hard to figure out how to correct it.

When I reduce my KH to 1 degree, my pH only gets as low as 6.8-7 (which is FINE, I know, I know) but now I have no KH. Is this bad?

Welp. if that were my water, I would surely be keeping an eye on it when I started injecting CO2. Kh is what helps buffer (resist, work against) changes in PH. Injecting CO2 will definitely produce carbonic acid, so the PH will drop.

I've never had a pH crash before, but I've also never had a successful soft water aquarium and I don't want a pH crash. I guess the best way to get lower than this on my pH is to add CO2...

Just a note here that many people suggest that for fish health, the stablility of PH (and other water parameters too) may be more important then the absolute values. The fish can adapt to a lot of conditions but don't do well with rapid change. Breeding is another matter though.

In your case, maybe you should strip your water to the point where you achieve the KH you want (which is what, if you don't mind me asking). Obviously you won't have any GH, but you can add this back using a buffer (like R.O. Right).

My Kh from the tap today is in the 120 ppm range and Gh around 90 ppm. PH is up around 8.4 or so. My test kits are Hach commercial water kits although some of the reagents are a bit dated. I am still deciding how well I trust the readings.

RO Right. Right . Yours is not the only account I have read stating that they failed to get increased Gh readings using this product. What is in it and why don't the test kits pick it up? What test kit were folks using and what test methods did those kits use?. Without answers to these questions I am reluctant to use it. Perhaps I will throw some dollars to the wind and see what my results are.

Kent has some other ph buffer/controller products that, if you believe what the literature says, you could use to make a water that is well buffered at a lower PH. I have not experience with these products what so ever. If you try them, let us know how it goes.

I wish you luck and hope for your best success.

 

[jsoong]

I believe most test kits work by acid titration and really cannot distinguish between anions although unless you have some really strange water, they are most likely overwhelmingly bicarbonates (HCO3) anyhoo.

Not trying to pick an argument .... trying to learn something new here.

I have always read that the KH kits will only measure carbonates. As I understand it, in acid titration, you add acid until the pH drops past a certain value. That pH value would be calibrated against carbonates, true? So if your water has a buffer that has a Ka less than that value, it wouldn't be detectable by the kit, as that buffer would still be ionized when the KH test color changes.

 

[DSenn]

OasisKeeper-

I am not aware of the other Kent products, but I have been investigating the Seachem Buffers a lot recently, and here is a link that is written by someone who swears by them:

www.ventralfins.com - B. Macrostoma Pages Heading #3, under lowering pH

It would seem that if you mix some of the Alkaline Buffer into the R.O., and then a little of the Acid Buffer afterwards, you can reach a low pH and still have some Carbonate Hardness. The drawbacks of this product-at least what I have heard form others-is that this is not an 'actual' buffer. I'm not exactly sure what that means, but I know it is neither carbonate or phosphate based.

In terms of your water, it doesn't seem to me that your GH and KH are that far off from each other. It sounds like we are both trying to soften our water. Like I said before, I currently just mix my R.O. in with some tap. What readings are you going for?

As far as the R.O. Right goes, it should be picked up on ANY test kit, in my opnion. I might try and get some of those Seachem products tomorrow. I think they make something called Equilibrium, which sounds kind of like R.O. Right.

In your opinion, do you think more frequent water changes would help me if I keep a low KH? I was thinking that if I did more, I would replenish the KH with the water changes, but I'm not sure.

Thanks for the help, keep in touch.

 

[DSenn]

jsoong-

Are you saying that my GH test kit won't pick up the hardness added by the R.O. Right because there is no KH?

 

[OasisKeeper]

Not trying to pick an argument .... trying to learn something new here.

I have always read that the KH kits will only measure carbonates. As I understand it, in acid titration, you add acid until the pH drops past a certain value. That pH value would be calibrated against carbonates, true? So if your water has a buffer that has a Ka less than that value, it wouldn't be detectable by the kit, as that buffer would still be ionized when the KH test color changes.

My understanding is as follows:

The test is indicating by means of a PH shift across the indicator boundaries (blue green to pink for Bromo Green to Methyl red). The acid, sulfuric in the case of the Hach kit, can't distinguish carbonates from any other negative ion. They may be carbonates, bicarbonates, silicates, borates, phosphates, or hydroxide. It will just neutralize any that are there until enough are neutralized for the indicator to shift and you stop adding the acid. You are actually just pushing on the buffer with acid until it gets used up.

But unless your water is really screwy, these will be overwhelmingly carbonates and bicarbontes anyway, so the test just assumes that to be the case.

Here are some commercial carbonate hardness test strips for example. Take a look at the notes and the interferences.

I be delighted to learn that our tests are really measuring only the correct ions, but after a fair amount of reading, I don't think this is the case.

Let me know what you think. This stuff can make your head spin.

 

[OasisKeeper]

What readings are you going for?

Healthy fish and healthy and growing plants.

What am I going to do? Probably a 1:1 tap/RO mix, put it in the tank and see how it goes.

When I had my reef, I did a lot of automation to hold all the water parameters as tightly as I could. But in the end, the best test was always to look at the animals and stick my nose over the tank and take a big whiff. That told me things sooner then the instruments ever did.

 

[jsoong]

jsoong-

Are you saying that my GH test kit won't pick up the hardness added by the R.O. Right because there is no KH?

I am saying that the GH test kit can't pick up the hardness in RO right because there is no GH! <I am sure there is lots of KH in the buffer.>

GH kits only pick up Ca & Mg, so if there isn't a lot of it in ro right, you won't pick it up. And you can have lot of KH without GH (baking soda is an eg.)

 

[jsoong]

My understanding is as follows:

The test is indicating by means of a PH shift across the indicator boundaries (blue green to pink for Bromo Green to Methyl red). The acid, sulfuric in the case of the Hach kit, can't distinguish carbonates from any other negative ion. They may be carbonates, bicarbonates, silicates, borates, phosphates, or hydroxide. It will just neutralize any that are there until enough are neutralized for the indicator to shift and you stop adding the acid. You are actually just pushing on the buffer with acid until it gets used up.

But unless your water is really screwy, these will be overwhelmingly carbonates and bicarbontes anyway, so the test just assumes that to be the case.

Here are some commercial carbonate hardness test strips for example. Take a look at the notes and the interferences.

I be delighted to learn that our tests are really measuring only the correct ions, but after a fair amount of reading, I don't think this is the case.

Let me know what you think. This stuff can make your head spin.

My thinking is this, the indicator will change at a specific pH. <What that is, I can't found out.> For the sake of argument, lets say that is 7.0. If your water has CO3 & PO4, and a pH of 8, the PO4 will mostly be unionized (& not participate in the pH). As you add the acid, you would be changing the ionized CO3 to unionized form, as the pH gradually drops. At 7, the color changes. Since you only add enough acid to un-ionize the CO3 (as the PO4 is unionized at the starting pH), you are essentially measuring only then CO3. <Also, if you have a strongly buffered solution at a low pH, lower than the indicator change pH, you add the first drop & there is a color change, so you say low KH .... even though there is lots of buffer you don't measure.>

It would be nice to know the color change point. Basically, you would be measuring all the buffers that have a Ka above that point.

Anyway, I agree with you that this is mostly an academic argument. In practice, Kh is just carbonates.