Adding Trace Elements after Testing

Simon_M · Jan 2, 2023

I have been testing my DT water before adding Trace Elements. Using RS Foundation and (soon) RS Trace Colours A, B C and D.

I measured Calcium and it measures 402 ppm using my Hanna Tester. My target is 450 ppm. I'm adding Foundation using my Doser over seven days.

The total addition is 150ml of Calcium Foundation Liquid.

According to the instructions for TS Trace Colours, the Trace Elements can be added in ratio 1:20 to Calcium for Mixed Reef tanks. They also suggest dosing based upon Testing.

The problem I have, is knowing if the RS Potassium Test can be relied upon. I don't get the colour shift from purple to blue until I have titrated two 0.5ml of liquid.

This would imply that I have to use a lot of Potassium if I adopted the Test/Dose method. Alternatively, if I used only the uptake of Calcium, then it's only 7.5ml.

I also tested Iron that was marginally low and Iodine that was OK. My tank is lightly loaded with corals (not much SPS) and I do 10% RS Blue Bucket water changes weekly.

My suspicion is that the RS Test for Potassium isn't working for me, since I have a hard time detecting the colour change. Perhaps my eyes are at fault?

I had the same thing with Magnesium using the RS Test. It always was off the scale at 1600 ppm. I had LFS test it and they say it's 1300 for their water and 1350 using a Salifert Test I had on the same water. Again, perhaps my eyes are the issue? Titration colour changes are subjective. In the RS Test for Potassium, it is a subtle colour change. For the other two tests it is a colour chart comparison. Like RS Nitrate and Phosphate, they are colour comparison which I don't have issues with.

The RS instructions for the Trace additives are Test/Dose for ULNS Systems. I wanted to adopt this for a Mixed Reef, but I have a hard time believing that the uptake of Potassium is really twice what the Test is designed for. For me it's just not working. 10% water change is replacing the equivalent of all the tank water five times a year, so uptake of Potassium shouldn't be an issue for my DT.

For Trace Colours, there seems to be four strategies: don't bother, trace by Calcium uptake, trace by element e.g. Potassium, trace by instruction e.g. add 3ml/week regardless. I'm favouring the Calcium uptake since I'm having a hard time believing the RS Potassium Test. FWIW, for MAgnesium, I had my RS salt tested and the reagents replaced - still didn't work (for me).

Simon

taricha · Jan 2, 2023

A few points to reply to

Simon_M said:
I measured Calcium and it measures 402 ppm using my Hanna Tester. My target is 450 ppm.

Simon_M said:
According to the instructions for TS Trace Colours, the Trace Elements can be added in ratio 1:20 to Calcium

Dosing trace elements by calcium usage may make sense for most trace, but maybe not for all.
And it certainly doesn't make sense to tie trace elements to your wish to raise Ca by 50ppm. It's meant to be tied to ongoing Ca dosage.

Simon_M said:
The problem I have, is knowing if the RS Potassium Test can be relied upon. I don't get the colour shift from purple to blue until I have titrated two 0.5ml of liquid.

This would imply that I have to use a lot of Potassium if I adopted the Test/Dose method.

if you had to use 2x as much titration liquid, that should mean your potassium is quite high, not low. Right?

Simon_M said:
I also tested Iron that was marginally low and Iodine that was OK. My tank is lightly loaded with corals (not much SPS) and I do 10% RS Blue Bucket water changes weekly.

you got non-zero values for Fe and iodine? Declare victory. Your water changes are working in this area.
Red Sea's Fe target (and any detectable value) is much higher than natural sea water.

Simon_M said:
I had the same thing with Magnesium using the RS Test. It always was off the scale at 1600 ppm. I had LFS test it and they say it's 1300 for their water and 1350 using a Salifert Test

That's most everyone's experience. Red Sea reads a couple hundred high on Mg, and people like salifert.

Simon_M · Jan 2, 2023

Agree with most things except what their K Test shows:

The RS Potassium Test is the opposite of most tests e.g. 0.01ml of titrant represents a fall of 3 ppm K. So 470 ppm is indicated by 0 ml titrant used down to 320 ppm when 0.5 ml is used. My problem is requiring double this amount, so implying 170 ppm. I just don't believe it.

On a lightly stocked tank and limited coral (water changes may be almost sufficient), it seems odd that two of the tests e.g. Fe and I are OK and K is very far off. More likely I don't read the test properly or the test reagents/procedure is suspect. Before giving up on the test, I may try testing my next batch of salt mix as that should be about right e.g. not depleted.

The dose rate for Calcium depletion is 1ml of colour (4x) for each 20 ppm deficiency. RS suggest monitoring it for 4 days and adding the 4 day deficiency and then 1/4 per day thereafter. In my case, it would be what's required to restore the levels and then measuring for 4 days and using their formula.

The measure based upon Calcium uptake has been criticised (by some) because it may apply to SPS, but softies and some LPS may also use up trace elements but not deplete (or lower uptake of) Calcium (as much). This would result in some trace elements being added for SPS and less for other types. Since it is better not to over do it, that would be a conservative approach.

The potassium test is purple to blue, so not so easy to see a shift e.g. not red to blue. I could be confusing the start point e.g. starting with (ignoring) a very high Potassium level?

The Magnesium Test may not be accurate, but RS say that it can be "checked" e.g. take 10ml of Mg Foundation and mix with 990 ml of deionised water and test to show 1000 ppm Mg +/- 20 ppm. If their test results were so far off then I assume thay would want to correct it by changing the reagents or the amount of sample water to correct a discrepency? Perhaps there is a similar way to test their Potassium test using the trace colour for Potassium?

Randy Holmes-Farley · Jan 3, 2023

I also do not believe that 170 ppm potassium is a likely result and I would not add the huge amount needed to boost it without checking, preferably by ICP. In general, there is NO a priori reason that potassium is depleted in all aquaria. It never depleted in mine.

I am among those who think a calcium based trace element addition method is flawed.

The Red Sea iron recommendation is incredibly high, and IMO, may be so high just so their kit can detect their recommended level. I also do not know if the kit is accurate. What level did it report?

taricha · Jan 3, 2023

Simon_M said:
The RS Potassium Test is the opposite of most tests e.g. 0.01ml of titrant represents a fall of 3 ppm K. So 470 ppm is indicated by 0 ml titrant used down to 320 ppm when 0.5 ml is used. My problem is requiring double this amount, so implying 170 ppm.

Thanks! Forgot that's how my salifert K kit worked also.

Simon_M · Jan 3, 2023

RS Trace Colours Test Kit range and OK values:

I - Iodine-2 test is 0 ppm - 0.09 ppm where 0.06 ppm is the OK value.
K - Potassium test is 467 ppm down to 320 ppm where 400 ppm is the OK value.
Fe - Iron test is 0 ppm - 0.5 ppm where 0.15 ppm is the OK value.

Only the Potassium test requires more than the expected amount of titrant to make a change. As discussed, there isn't much to absorb/change the Potassium, so getting a indicated value of 170 ppm simply doesn't make sense.

If I was dosing based upon Calcium uptake, then I would be adding 7.5ml of each of the Colours. If I was to attempt to dose for a ridiculous shortfall of Potassium, then it would be more than the whole bottle. For something that barely gets used it suggests the Red Sea test is completely flawed.

Another RS Test Kit I have is Magnesium, range and OK:

Mg Magnesium test is 1600 ppm - 760 ppm where the OK is 1300 - 1350 ppm.

Like the Potassium Test, the Magnesium titration test doesn't work (for me). It consistently record higher than 1600 ppm. One test with RS is to use their Foundation to prepare a "standard" e.g. 10 ml in one litre deionised water for 1000 ppm. I tried this with 3 ml (total) in 250 ml for a 1200 ppm solution.

Using my Hanna Test Kit for Magnesium, I get 1095 ppm and using Salifert I get 1100 ppm but with RS I get more than 1600 ppm e.g. off the scale. This indicates to me that this Red Sea test is also completely flawed.

BTW, getting about 1100 ppm when preparing a 1200 ppm solution is within the margin of error because 3 ml down 5% is only 0.15 ml down (easily done) and the Red Sea Magnesium Foundation may not itself be 100% accurate.

I could also check my Hanna Test Kit for Calcium e.g. use 1 ml in 435 ml to get 460 ppm. The Hanna, Salifert and Red Sea are all reading about the same, but it would be good to confirm that they are accurate or that my testing method isn't flawed.

So for the Trace Colours, I'm in no rush to dose lots of Potassium because it doesn't make sense that it was used and require replacement.

For my DT, the total Calcium reduction has only been 45 ppm e.g. 10% water changes alone have been (mostly) sufficient to prevent it falling too far. The dosing that I started will restore it in about a week using very small daily doses.

Although the Red Sea Calcium uptake methodology is indeed a bit suspect, dosing 7.5 ml of the Potassium Supplement (e.g. the same across all the colours) will make a negligible dent in the supposed loss. For that I would need several bottles worth - not going to try this. So whilst I like test and dose, I'm not going to adopt it for Potassium.

Simon

ELChingonsReef · Apr 10, 2023

Randy Holmes-Farley said:
I also do not believe that 170 ppm potassium is a likely result and I would not add the huge amount needed to boost it without checking, preferably by ICP. In general, there is NO a priori reason that potassium is depleted in all aquaria. It never depleted in mine.

I am among those who think a calcium based trace element addition method is flawed.

The Red Sea iron recommendation is incredibly high, and IMO, may be so high just so their kit can detect their recommended level. I also do not know if the kit is accurate. What level did it report?

I completely agree randy. I got myself into trouble with calcium based trace element addition. We talked about this a couple months ago you and I in a different thread about aluminum levels in my system. I was thankful you could clarify that the level of aluminum in my system was not dangerous but still it came from calcium based trace element addition. I don't use that product anymore. The aluminum has come down. I had another question for you about aluminum. Is it possible that the packaging from frozen fish food , that's aluminum, can it contribute to high levels of aluminum?? For example frozen brine comes in those cubes. They are packaged in a plastic tray with aluminum adhesive to seal them. It's not entirely impossible that one of those peices of aluminum is buried in my sand bed. Or even that food being In contact with the aluminum backing could possibly cause high icp aluminum results. Sorry my question is a little bit off topic but when you combine a trace element you dose by calcium consumption that has aluminum in it that's not accurate with food that's packaged with aluminum. I wonder if there's a connection.

Randy Holmes-Farley · Apr 11, 2023

Luv4tangz said:
I completely agree randy. I got myself into trouble with calcium based trace element addition. We talked about this a couple months ago you and I in a different thread about aluminum levels in my system. I was thankful you could clarify that the level of aluminum in my system was not dangerous but still it came from calcium based trace element addition. I don't use that product anymore. The aluminum has come down. I had another question for you about aluminum. Is it possible that the packaging from frozen fish food , that's aluminum, can it contribute to high levels of aluminum?? For example frozen brine comes in those cubes. They are packaged in a plastic tray with aluminum adhesive to seal them. It's not entirely impossible that one of those peices of aluminum is buried in my sand bed. Or even that food being In contact with the aluminum backing could possibly cause high icp aluminum results. Sorry my question is a little bit off topic but when you combine a trace element you dose by calcium consumption that has aluminum in it that's not accurate with food that's packaged with aluminum. I wonder if there's a connection.

Foods can be a source of aluminum, independent of whether they have aluminum packaging, but usually those effects aren't huge since the volumes added are small:

Chemistry And The Aquarium: Aluminum In The Reef Aquarium

In this article I will give some details of aluminum in natural seawater, and will discuss the sparse literature on the toxicity of aluminum ions to marine organisms.

reefs.com

from it:

"Foods are, of course, another potential source of aluminum. In a study of the amounts of different elements in certain foods, Shimek presented the results shown in Table 2. The values have also been normalized to show the amount of aluminum in the foods in relation to the number of calories provided. Clearly, if aluminum is of primary concern, brine shrimp (highlighted in red) should probably not be on the menu.

If you fed 5 grams of it to a 100 gallon tank every day, that would amount to 5 g x 120 mg/kg = 0.6 mg/day or 219 mg/year. Added to that 100 gallons (379 L), that gives an addition of 219 mg/378 L/y = 0.6 ppm per year. The other listed foods would, of course, contribute much less. Unfortunately, these sorts of raw measures of aluminum say nothing about what form it is in. For example, it might be present as soluble aluminum, or as insoluble (particulate) forms."

ELChingonsReef · Apr 12, 2023

Randy Holmes-Farley said:
Foods can be a source of aluminum, independent of whether they have aluminum packaging, but usually those effects aren't huge since the volumes added are small:

Chemistry And The Aquarium: Aluminum In The Reef Aquarium

In this article I will give some details of aluminum in natural seawater, and will discuss the sparse literature on the toxicity of aluminum ions to marine organisms.

reefs.com

from it:

"Foods are, of course, another potential source of aluminum. In a study of the amounts of different elements in certain foods, Shimek presented the results shown in Table 2. The values have also been normalized to show the amount of aluminum in the foods in relation to the number of calories provided. Clearly, if aluminum is of primary concern, brine shrimp (highlighted in red) should probably not be on the menu.

If you fed 5 grams of it to a 100 gallon tank every day, that would amount to 5 g x 120 mg/kg = 0.6 mg/day or 219 mg/year. Added to that 100 gallons (379 L), that gives an addition of 219 mg/378 L/y = 0.6 ppm per year. The other listed foods would, of course, contribute much less. Unfortunately, these sorts of raw measures of aluminum say nothing about what form it is in. For example, it might be present as soluble aluminum, or as insoluble (particulate) forms."

Thanks randy I appreciate your advice. Thanks for always helping me out when I have a question.