Clarify Something Please

JamesBC

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Apr 6, 2008
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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....
 

shane

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Nov 29, 2006
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I believe Chuck's calculator has both the weekly dosing values and the x times/week values shown.
 

shane

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Sorry, my mistake.

I use Nutri Calc V1.9.3 by Cherniak Software.
 

VaughnH

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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!)
 

JamesBC

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Apr 6, 2008
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"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.
 

orion2001

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Mar 27, 2008
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Hi James. Here is the link to NutriCalc:
http://www.cherniaksoftware.com/homepage/Data/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.
 

orion2001

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Mar 27, 2008
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JamesBC;24655 said:
"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.


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.
 

Carissa

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Jun 8, 2007
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orion2001;24656 said:
Hi James. Here is the link to NutriCalc:
http://www.cherniaksoftware.com/homepage/Data/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.

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.
 

orion2001

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Mar 27, 2008
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What you say is true Carissa, but isn't the point of EI, to have a standard dose and not worry about measurements and uptake rates and exact numbers? If you did want to maintain exactly 30ppm levels in your tank, then you'd need to do what you say. ie, dose 30ppm right away and then if you know your plant uptake rates and have done extensive testing, then dose accordingly to compensate for the uptake rates.

I guess with EI the idea was to move away from being exact. So if you don't think that your plants are going to have an uptake of over 30ppm in a week, then this strategy should work fine. As long as you still have enough nitrates in the water for the plants not to be limitted by them, it should work well (As far as I understand).
 

Carissa

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Jun 8, 2007
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Point taken. I think uptake rates are still important though even if you are doing ei, at least to some degree. If someone were adding 30ppm of nitrates every week and the plants were not keeping up, you could get nearly up to 60ppm over time. I've heard people say that this is not toxic, but I've lost fish at 40ppm from overdosing fertilizers accidentally. On the other hand, if the tank is very full of fast growing plants and co2, only dosing 4ppm per day may not keep up to demand, this has also happened to me (a calibrated nitrate test kit showed that my nitrates were 0, two days after adding 20ppm). Not that extensive testing is needed or at least not that often, but it can be guessed pretty reasonably by looking at your tank setup (co2, lighting, amount of plants, type of plants, fish load).

Also, there are some things that you might want to maintain at certain ppm's, not just >0, such as calcium and magnesium. These should just be added weekly at the dose that you need to bring the tank up to the level you want, if you need to add them. Granted this is not the same as fertilizers that get used up quickly.
 

VaughnH

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EI was set up to be "Fertilizing for the Lazy", or maybe "Fertilizing for Dummies". You have a choice of using EI, which means looking up your tank size in a table, then dosing per that table, followed by changing about half of the water in the tank every week. Or, you can measure what concentrations of the various nutrients are in the tank, calculate how much of each fertillizer is needed to increase that level to some "target" value, dose, measure again later, dose again, etc. If you enjoy doing it that way you should do it that way. Many people do enjoy the chemistry of keeping aquatic plants, and enjoy trying to read the plants to determine what is possibly in short supply, calculating what needs to be added, etc. Those people should do their fertilizing by a method that they enjoy.

Tom has pointed out that EI dosages are not cast in concrete either. They are supposed to be enough to cover the plants needs for any reasonable plant load and light intensity. But, that means they are more than necessary for many tanks. He has suggested starting with the table amounts, then gradually reducing them until you see an adverse effect on the plants, then going back to the dose that didn't give that adverse effect. That is the "semi-chemist" approach - EI Pro, I guess. I happen to fit the original description of the plant keeper the EI system was designed for, so I just follow it.
 

Tom Barr

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Test kits are not exact and few use them to any degree of accuracy anyhow.


There is a large amount of hypocrisy with folks that insist that we test to maintain good conditions and precise tolerances for ppm's when they themselves do not measure correctly to start with.

I'm a bit more honest about things.
They want to get lost in their own pre drawn conclusions, that's their business, but they will never win a debate.

Some common sense should also be applied, plants can and do grow in wide range of nutrient ppm's. It's not a pre set ppm with no variation.

If someone really wants to do this, I can certainly help them do it, but they might not like how far they need to go to achieve that goal.

And that's the rub, they wanna do a lazy short cut while telling folks to do all this added labor because it's "needed". When you start taking lots of short cuts, there are trade offs, you start losing the very thing you claim you want to achieve.

So where is the balance?
EI does this well.

You can reduce the labor of water changes using some test kits if you want.
You can also not do either water changes or test kits and eye ball the plants.
You can add ferts to the sediments, AS, mud, etc, and not dose much, or go lean in the water column with rich sediments(ADA's and other folk's approach) and no test kits. However, ADA and other folks still suggest large frequent water changes

And poor CO2 will doom any method here and folks often blame the dosing, not their poor use and extremely poor measurement of CO2 and general high light:rolleyes:

And around and around we go.
History repeats itself way too many times here in this hobby.
They assume huge liberties with light and CO2, without any critical investigation, then blame nutrients, or ADA, or themselves("I just cannot grow plants"), EI, PMDD etc.

All while using poor test methods and cheap 6-12$ test kits.
You can get some accuracy out of some test kits that are cheap, but some you cannot.

We all get lazy and take short cuts, but a wise person will realize this and set up a method to reduce the trade offs.

I do not like water changes either, but I set things up to automate or make it really easy for myself.

Then no test and no labor involved for water changes.

That's a truly lazy and smarter hobbyist.

Then it's most gardening goals.

Regards,
Tom Barr