Ok, after doing alot of reading, I am getting ready to try a planted tank. Have the CO2 bottle, guage, bubble checker ect ect ready to go.

My question is on EI dosing, using dry fert and Chuck's Calculator. Say I mix up a solution for K2SO4 so that 1 ML of it will give me 1ppm of Potassium. Suggested tank target lvl is 20ppm. If I dose 3 times a week, would I dose 20ml of the above solution or divide that into 3 equal amounts?

Now I think I have a good understanding on plant uptake, which would cause the amount of doseing to change somewhat, along with light and CO2, just I can't seem to get it though my thick skull about how much to dose if doing it say 3 times a week.

Thanks for any help, and maybe send a smart pill to me....

I believe Chuck's calculator has both the weekly dosing values and the x times/week values shown.

Not that I can see, or if it does I don't understand it. Using v1.0i

Sorry, my mistake.

I use Nutri Calc V1.9.3 by Cherniak Software.

James, using the EI method doesn't require calculating dosages per Chuck Gadd's calculator or any other. The method is based on estimating the maximum amount of each fertilizer that could be needed for a given size tank, dosing that amount, knowing that even if you are dosing too much you aren't going to do any harm, then doing weekly big water changes to prevent any accumulation of any of the fertilizers. The estimations have already been done, and are in tables ready to use.

I'm not saying this is the only or even the best way to fertilize, but it is an effective way. If you decide to use a method that sets target concentrations of each fertilizer in the water, then a calculator is very useful.

You don't even need a calculator for EI dosing if you premix the fertilizers and dose them as liquids. You just put X doses of the fertilizers in a bottle with X times the amount of liquid you want to dose, shake it up, then dose X amount of that each time. (Chemistry for dummies like me!)

"You don't even need a calculator for EI dosing if you premix the fertilizers and dose them as liquids. You just put X doses of the fertilizers in a bottle with X times the amount of liquid you want to dose, shake it up, then dose X amount of that each time. (Chemistry for dummies like me!)"

OK, I am sorry but this just does not make sense to me, X is what, enough to get 20ppm in the tank, dose this 3 times a week? Now I understand you are not trying to get exactly 20ppm, but more around that mark. So what you are saying is the solution I have, I would need to add 20ml of it, which would bring the tank up to 20ppm more or less, and I would do this each day.

Hi James. Here is the link to NutriCalc:
http://www.cherniaksoftware.com/home.../NutriCalc.exe

I haven't used it myself but it seems useful. However Chuck's calculator should be good enough. All you really need to know is what level due you want your ferts to be at in your tank over a week.

For example, if you want Nitrate levels of 30ppm sustained in your tank till you do your weekly water change, then using Chuck's calculator calculate how many grams of KNO3 you require to have 30ppm of NO3 in a 10 Gallon tank (Assuming you have a 10G tank). Now that you know how much would give you 30 ppm, dissolve that KNO3 in a large enough amount of water, so that you can split it up into either daily doses (1/7th of the total volume you dissolve in), or 3x a week (1/3 of the volume you dissolve in being each dose).

I hope that makes sense to you. Do the same thing for the other nutrients.

Yes, thank you Orion. That does make sense to me now.

Thank you

Hey James. You should not dose the solution that would give you 20ppm in your tank 3x a week. That will raise the levels up to 60ppm in a week assuming no uptake by the plants. What you want to do, like I explained in the post above is to make a solution using Chucks calculator that you know will add 20ppm to your tank when you dissolve the whole solution in it. Then split this solution into as many doses as you wish to do over a week.

Chuck's calculator is a little confusing for doing this. First specify the amount of water to dissolve in as 100ml (makes the math easy). Then do a trial amount for the KNO3, say 1gm, or if you don't have scales, 0,5 teaspoon. Lets say we input 0.5 teaspoon. If you set the tank size to 10 gallons it should tell you that each ml of the solution will add 0.45 ppm Nitrate.

Now this amount is per ml, so if you add the whole 100ml into your tank then you would have 100x0.45ppm=45ppm of nitrates in your tank. If you want to achieve 30ppm, then dial down the dosing amount (maybe 0.3 teaspoon which gives 27ppm) and try again. Now that you know how many grams of KNO3 would give you 30ppm (or close to 30 ppm) in your tank, then dissolve this amount of KNO3 in a convenient amount of water. You don't actually need to dissolve it in 100ml of water. That was just convenient in figuring out how many ppms the specified amount of KNO3 would add to your tank. So if you want to have NO3 levels of 27ppm in your tank, and want to dose 3x a week, I'd dissolve 0.3 teaspoon in 300 ml of water and dose 1/3rd of it, ie a 100ml of your solution every time.

I hope this is making sense. Feel free to ask me questions on this. An easier way to do all this really is to use the percentage info in Chuck's calculator page:
Calculating dosages of fertilizer elements for a planted tank

It says that in KNO3, NO3 forms 61.3% of KNO3 by weight. So if you add 1gm of KNO3 to your tank, you are actually adding 0.613gms of NO3. Now ppm actually is the same as mg/l (miligrams per liter). So if you add 1 gm of KNO3 to a 10 gallon (37.85 liter tank as calculated in chuck's calculator), you are adding 0.613gms or 613 mg of NO3 to 37.85 liter of water.

So the ppm for NO3 added to tank would be 613/37.85=16ppm. You could do the calculations yourself by this technique or rely on Chuck's calculator. Whichever works for you.

But this would be assuming that you want to only add a total of 30ppm per week. If you only add a portion of that every day, your total nitrate will never be up to 30ppm. (adding 1/7 of the amount that will bring you up to 30ppm will only bring you up to 4.28 ppm the first day, then 8.56 the next day at the most- but probably much of that initial 4.28 will have been taken up by the plants already so this would only be good for a lean system). If, on the other hand, you want to maintain your nitrate at 30ppm at all times, you need to dose the full amount initially that will bring you from 0 up to 30ppm and then dose throughout the week to keep up with the plant intake (usually 2 - 3x/week or so for high light/co2, but only 1x/week for non-co2 or less). Then your 50% water change removes the excess nutrients that may have built up from overdosing. Hope this makes sense. If you want 30ppm of nitrate in your tank at all times, you have to add the full 30ppm on the first dose. The additional doses during the week are meant to keep up with plant uptake and that's why they would vary depending on co2, lighting, and fish load. Some tanks can go from 30ppm to 0 in two days, others take two weeks. In the first example you would have to dose the full 30ppm amount 3 - 4x/week, in the second, you wouldn't have to redose until you do your water change. The water change just ensures that you can never end up with as much as double what you put in each week. The suggested dosing regimen (3x/week) is based on average uptakes for a full plant load in a high light co2 tank. This may need to be scaled back for your particular setup.