Thanks! Potassium is one of those elements that generally keeps itself in line for most people, but it's absolutely critical for life as we know it. Worth testing at least once just to know what your tank runs at, I think. For instance, too much Potassium can stop your heart - it's that critical to have at the right level.

Mohamad Osman yep! That's a great way to do it as long as the ice melt doesn't have other stuff in it. Sounds like you found a good brand though!

Interesting - I hadn't seen that they're unreliable for these tests. Can you direct me to a thread or source? I'm curious!

@@ReefMan I live in Portugal but I follow what's going on in the Brazil reef world. Not long ago Triton made a push to establish themselves as a viable method for managing a reef there. Their prices were extremely high, the minimum wage would allow you to get 2.5 ICP tests there. That generated a counter reaction from many hobbiests, that led to many of them conducting their own researches and pushing not only Brazillian representatives of ICP tests, but also head offices to answer a set of very detailed questions about the tests. Many hobbiests copy pasted the questions and sent them to many companies. They couldn't be ignored and the answers from the ICP companies were far from satisfatory. A few Brazillian specialists in ICP testing came out and explained why they consider ICP testing inadequate for reef tanks for a variety of reasons ranging from the ICP machines to the operation of those machines. I will try to translate an abreviated version of those questions and answers and I will post them here.

@@ReefMan Here are the questions: 1- I would like to know if it´s true that the ICP-OES can´t measure Iron, Chrome and Cobalt if these elements are at the seawater concentration or below ? 2 - What is the standard deviation for each element in the ICP-EOS test ? 3 - I would like to know if the ICP machine is calibrated before each ICP test or after a period of time or a number of tests ? 4 - How many ICP tests one single ICP machine can do per day ? 5 - I would like to know if it´s true that is required to do a mechanical filtration in the aquarium water sample before I send it to the ICP lab ? 6 - I would like to know if it´s true that I need to add nitric acid in my aquarium water sample before I send it to the ICP lab ? Because I read an article written by a Pos Doctor and he wrote in his article that the water sample can be contaminated and the water sample can have a lot of chemical transformations between the time I got the sample from my aquarium and when the sample arrives in the ICP lab. Is this true ? 7 - I would like to know when my ICP test shows zero in any element, if I can trust that is really zero or the ICP-OES is not accurate enough to show me when the elements are in very, very low concentration in my aquarium water sample ? 8- I would like to know if a variation in pH and temperature in my aquarium water sample through shipping between my house / aquarium and ICP lab could give me wrong results in the ICP-OES test ? 9-If I send five samples of water from my aquarium ( the same sample water at the same time / day ) all the ICP-OES will show me the same results in all elements ? Or each sample could show different results ? I read an article from Randy Holmes and Hans Balling, read below : Randy Holmes : The reason that I am describing the analysis method is that it is important for interpreting the results in that it is essentially a way of counting atoms and ions in the sample. The method cannot determine anything about the nature of those atoms, except what they are. So, for example, a single result is obtained for something like iodine, even though there may be many forms that the iodine takes in the water sample, including iodide (I-), iodate (IO3-), iodine (I2), hypoiodate (IO-), hypoiodous acid (HOI), and many different organic forms, such as methyliodide (CH3I). All of these end up in the plasma as the same thing. Hans Balling : Not all elements can be analyzed by the ICPOES and ICP-MS methods, because of its complexity behavior. Iodide (Luther and Cole, 1988) and iodate (Herring and Liss, 1974) can best be measured by a polarographic method, the voltametric method in which the current is measured as a function of applied potential, using a dropping mercury electrode. The specific method for iodide is called cathodic stripping square wave voltammetry (CSSWV) and for iodate differential pulse polarography (DPP). Measuring trace elements can best be carried out by specialized laboratories. 10- I would like to know if it´s true that ICP-OES test is not good enough for the element Iodine ? 11- I saw a vídeo on youtube from one reef keeper , and he sent his aquarium water sample to three different labs ( Triton, ATI and Aquaforest ) and all three ICP tests were completely different. How can I fix the elements in my aquarium water if each ICP test shows different results ? Can I really trust ICP-OES Test ?

@@ReefMan Here's the video where the answers are discussed. kzfaq.info/get/bejne/i9WjmaxhyrfYcoU.html

Lately I've been using Triton tests about once a month or so. I also have a Red Sea kit that I used to adjust the amount I needed to dose originally after Triton alerted me to it being low.

I bet that both those would work. You need to mix a known concentration and then do the match from there to figure out how much to dose. Potassium nitrate is another that you can use which will also add some nitrates

And yes, just mix them with RO water

@@ReefMan Thanks

@@ReefMan I just got an icp test back and my k was high. 600ppm what are the effects of high potassium?