# Dry vs Diluted ?'s



## Sterling919 (Jan 19, 2008)

Can someone explain or point me into the direction of an explanation as to why dry doses yield such higher levels over water mixed ones?

Using Chuck's Calculator (assuming I'm understanding it correctly) if you took 1 teaspoon and mixed it in say 8 ounces of water, you would only need to put about 13ml of the solution into 10 gallons of water to get the desired PPM. That same 1 teaspoon of dry fert just dumped into the tank would jack the PPM out of this world. 

Am I understanding it right that mixing it with water dilutes it down? Or am I just not seeing the whole picture and missing something? Is the solution (water mixed) just as strong (8 ounces) as 1 teaspoon of dry mix? Would the PPM level be the same between the two whether watered down first or dry dosed?

The way I'm seeing it right now, it makes more sense to dry dose cause you get higher PPM per dose. But at the same time...I'm thinking that I'm not seeing it straight....


I think you'd get the same PPM results with 1 teaspoon as you'd get with that same teaspoon in 8 ounces of water. The calculator is just saying you'd get a certain PPM by a certain ML if you mixed into a solution instead of dry...have I confused you as much as I've confused myself?


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## Zapins (Jul 28, 2004)

ppm means “part per million,” so if the desired concentration in the tank is 10 ppm that means that there are 10 parts of the chemical to 1 ,000,000 parts of water. 

Dry compound is highly concentrated, it is essentially 99 % chemical to 1% water that has condensed out of the air. 

If you take 1 gram of dry chemical and add it to 1 liter of water then add the 1 gram to a swimming pool of 100,000 liters your concentration of chemical is much higher in the 1 liter than in the pool since the 1 gram of chemical is much less spread out than it is in the pool.

Now if you take 1 mL from the 1 liter (1,000 mL) that was just mixed with 1 gram of chemical you are basically taking 1/1000th of a gram out. Compare this with taking 1 mL from the pool, which works out to be 1/100,000,000th of a gram of chemical in the 1 mL.

Adding liquid from a pre-mixed bottle of water is much easier and more precise when dosing your tank, because if you only need 1/1000th of a gram of chemical in the tank water how are you going to measure out 1/1000th of a gram of dry chemical without a really expensive scientific scale? It is far easier to get the tiny fraction of a gram of chemical that is required via diluting it down than add dry chemical directly, although if you had an accurate enough scale and good enough tweezers to pick up individual grains of chemical then it would work out to be the exact same thing in both cases.

Adding teaspoons of dry chemical to the tank isn’t usually a good idea, because it usually results in massively overdosing the tank with chemical (to the point of toxicity).


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## ray-the-pilot (May 14, 2008)

If you put 1 teaspoon full of a chemical in your tank, you put 1 teaspoon in your tank (that's easy).
If you put 1 teaspoon of a chemical into 500ml of water (this is about 100 teaspoons) then take one teaspoon of this solution and add it to your tank you've add:
1/100 x 1 teaspoon of the chemical. i.e. 0.01 teaspoons.
The remaining .99 teaspoons are still in the solution that you didn't use.


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## hoppycalif (Apr 7, 2005)

ray-the-pilot said:


> If you put 1 teaspoon full of a chemical in your tank, you put 1 teaspoon in your tank (that's easy).
> If you put 1 teaspoon of a chemical into 500ml of water (this is about 100 teaspoons) then take one teaspoon of this solution and add it to your tank you've add:
> 1/100 x 1 teaspoon of the chemical. i.e. 0.01 teaspoons.
> The remaining .99 teaspoons are still in the solution that you didn't use.


A wise person then saves that .99 teaspoons in that solution, and uses it to dose the tank, one teaspoon at a time, until the mixture is used up, 99 doses later. Or, you can just dump the bottle and start over each day.


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## Sterling919 (Jan 19, 2008)

And doing that would make me an idiot...haha...and my ferts would be wasted quickly. 

I figured it like you guys said it but I just wasn't thinking last night as late as it was.


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## Zapins (Jul 28, 2004)

It is ok to ask questions if you are unsure, even a little. Better to confirm than keep wondering or worse - do something wrong and have a disaster on your hands.


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## Sterling919 (Jan 19, 2008)

Well what I'm going to do is focus on my 40g breeder tank as my main planted tank. The 10g I have just seems to be to "iffy" and hard to deal with...especially for a newbie like me. I've not had a big amount of luck with that tank.

I'm trying to use Chuck's Calculator to figure how to dilute the ferts I got into something I can use in my tank without frying them and the fish. I don't exactly understand the workings of this even though it seems very simple and I feel like an idiot for not being able to get this. First off for the sake of this thread here is what I bought :

Potassium Nitrate - 1lb
Mono Potassium Phosphate - 1lb
CSM+B Plantex - 1lb

All came from AquariumFertilizer.com (which ships super fast). What I'd really like to know is how to combine these three into one diluted mix and use the PMDD method of 1 drop per gallon everyday. I also have a bottle of SeaChem Flourish but I'm thinking the Plantex is the same thing and maybe contains what Flourish lacks...I don't know. 

Now using Chuck's calculator I see two different solutions for the Potassium Nitrate. Both call for different target levels so how can you dose the same chemical for two different PPM target levels without raising the level of the lower PPM target level? That is one thing that confuses me and has had me scratching my head. Next on the mono potassium phosphate bag it gives directions to make this mix but it seems a rather large amount to keep stored. My frig is kinda full and my wife is a constant complainer who gripes about my hobby when she can...almost all the time lately. And then I don't think I've seen anything about dosing the Plantex.

Now I have seen the estimated dosing chart but I really like the idea of just dosing enough or less and doing it everyday...hence the PMDD. I'm new to this and haven't learned all the abbreviations and such for the chemicals yet. I've pretty much got the KNO3...atleast it's a start, right? 

Is there a way to combine those three ferts that I've got and then use the PMDD method to dose them? Or is there a method to combine the KNO3 and the mono potassium phosphate and just use the Flourish with the PMDD method until it's all gone so that I've not wasted my money in it? 

Any help or suggestions?


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## hoppycalif (Apr 7, 2005)

You can combine the macro fertilizers, KNO3 and KH2PO4, into one liquid mix, but you can't add an iron containing micro fertilizer mix into that same bottle. That causes the iron to be precipitated out as an insoluble substance that just settles to the bottom of the bottle.

To get to one drop per gallon as the dosage takes some calculations, assuming you don't want to just use the PPS Pro method, which is almost what you are describing. And, Flourish is a good trace mix to use instead of CSM+B, although I seem to recall being told there is no iron or too little iron in it.


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## Sterling919 (Jan 19, 2008)

Well that is what I'd like to do, combine the KNO3 and KH2PO4 together into one solution and use the PMDD method. Which I believe is 1 drop per gallon of aquarium water per day. I don't mind the estimated dosage method but I'm kinda lazy sometimes and don't want to do a 50% water change every week. Thinking about it...that probably isn't a bad idea...changing 50% of the water every week. Since a 20% water change would be about 10 gallons...in a 40g tank I guess we're only talking about changing double the amount of water. 

But at the same time...it seems like a waste of ferts to dose that much and then dump it out in a week. The dry ferts don't cost that much and from what I understand 1lb bags should last about 1yr even doing it this way. But at the same time I feel like that the PMDD is a better way which results in less product being "wasted" and a better way insure that you aren't over dosing the tank.

I believe that the Flourish contains a low amount of iron and could be part of my problem with some of my plants...not enough iron in the water. I guess I'll have to research that and see what I come up and then run my thoughts by you guys and see what you think. 

AquariumFertilizer.com offers a PMDD mix and I believe it contains the CSM+B mix too. So if I'm right are you saying it's a bad deal because of the iron? The KNO3 and KH2PO4 is what I have along the lines of macro ferts...should I have something else too? If I need something else, then from what they've got, what do I need to order? And then does anyone know how to mix them so I can follow the PMDD method?

Or am I wrong all the way around and should I just go by the estimated dosing method? And then from what I get by using Chuck's calculator...the methods of estimated dosing put you over the PPM limit or target range for your tanks volume. KH2PO4 for example... .25 teaspoon...1/4 of this dry will put you over the target level of 1 PPM. So if you do that 3 times a week...you are really over the limit by the end of the week. Isn't that bad? And if so, then wouldn't the PMDD be better?

Dry ferts are cheaper. I like being able to feel that 1lb and seeing that bag full of fert over that 4 or 8oz bottle of SeaChem stuff. Makes me feel like I'm getting more for my money. But the liquid stuff by SeaChem seems so much easier to dose and use than trying to do it by dry ferts.


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## hoppycalif (Apr 7, 2005)

PMDD did not contain any significant amount of phosphates. When that method was devised it was believed that phosphates were the cause of algae growth. Only later was it determined that plants need phosphates, too.

Have you looked at the Pfertz liquid fertilizers - costing a lot less than Seachem's but more than dry chemicals? They are dosed by the squirt, as I recall.


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## Sterling919 (Jan 19, 2008)

No I haven't seen those but I'll look for them now that I know about them.


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## LetDiceFly (May 30, 2008)

I also wanted to dose daily so I converted the dose by multiplying by 3/7. I then took a plain soda bottle and measured the volume of a capful. I then calculated how many capfuls it took to fill up the bottle (that number is given on the bottle). So I added enough fertilizer (measured on a gram scale) to make up that number of doses and mixed it with water. So now I can just add a capful of liquid a day. It is much easier for me to remember to do something daily than 3x a week.


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## freshyleif (Jan 9, 2008)

I just started to use dry ferts and still have some questions.
I have an 80g tank and according to the E.I. guide I should be using:
2 1/4 tsp KNO3 
3/4 tsp KH2PO4 
3/4 tsp CSM-B 
for the whole week. My question is why can't I just take my weekly dry amounts and mix them in 1 liter bottles then divide the liter by seven and dose that way. My other question is do I still need or have a reason to use flourish excel with this. I do have pressurized co2.
I mean it seems to me that that is the point right, to keep things simple. Calculating out caps from bottles doesn't sound like my cup of tea but maybe I just think it is more work than it is.
I also don't really want to have bottles of chemicals in my fridge for long periods. I get in enough trouble for all the aquarium related item in the house as it is without having to keep things in the food area.


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## Sterling919 (Jan 19, 2008)

I don't get into trouble for my aquarium stuff but I have to hear remarks about it a lot of the time. But I guess a 2 1/2 gallon bucket sitting on the porch with some dead plants in it really is a problem. It's nothing like the 52 pairs of shoes in a tote sitting at the foot of the bed...that never get worn.

Or the classic "why do you need more of that, you already have it" and then go to buy more shoes when there are already 52 pairs in a tote at home. And I won't even go into the hair clips and all that junk that litter the bathroom countertop....

Anyway...I agree...I'd really fudge that up if I tried to use that method of caps. I can't seem to figure out how to just be simple enough...but that does sound good to me though. I mean just pour a capful and then be gone...I like the sound of it.


You should have to use the Excel if you have CO2 and are using dry stuff that is the micro's. Someone correct me if I am wrong but I think I'm right...hope I am anyway.


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## LetDiceFly (May 30, 2008)

The Excel is just a alternative to CO2, if you are injecting CO2 I would recommend saving it in case you get an algae problem because it can act as a algaecide, although it isn't designed for that. Double doses of Excel can clean out a moderate algae outbreak in only a week. 

A Pepsi bottle cap is about 7ml. If you use a 1 liter bottle that is 1000 ml. 7/1000 makes 140 capfuls. If you are dosing daily than that is 20 weeks worth, so if you uses the doses you calculated for a week and multiply them by 20 you should have the correct concentration. 

Using your numbers below I come up with 15 tbsp KNO3 and 5 tbsp KH2PO4 to make 1 liter. The CSM-B would also be 5 tablespoons but that has to be made in a separate bottle.


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## freshyleif (Jan 9, 2008)

Thank you sterling919 and letdicefly for both of your points and calculations I am mixing up my solutions today.


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## Sterling919 (Jan 19, 2008)

Ok, somebody help me here...

Chuck's calculator says you need to mix 11 teaspoons into 250ml of water to get a solution that will yield 1ppm @ 1 ml. The target level of KNO3 is 5ppm for a 40g tank. So you'd dose 5ml at a time to get to the 5ppm target, right?

Ok...you can not...CAN NOT dissolve 11 teaspoons of KNO3 into 250ml of water. Or atleast I can't...I shook the bottle until the Lord came here and said "just give up son". So what did I do wrong? It's not hard to figure most of it out if you use this calculator but I can't get that amount to dissolve no matter what I do.

That equation is for Nitrate in Potassium Nitrate KNO3 from the pull-down menu at the top of the calculator. 

I haven't even tried anything past this. I assume I could double the water amount to 500ml and keep the 11 teaspoons and just dose 10ml instead of 5 to get to the target of 5ppm in the tank. Is that right? But that puts me in the situation that others have stated...I don't want to keep huge amounts of this stuff sitting around if it'll go bad, if I have to keep it in the fridge and considering I have two small boys. They spell trouble.


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## hoppycalif (Apr 7, 2005)

Solutions of inorganic salts, like KNO3 and KH2PO4 don't go bad and don't need refrigeration. You can keep the bottles of that mix under the tank without worrying about it deteriorating.

I really like the dosing bottles that look like:









You can dose the amount the little dose container at the top holds, and the bottle then lasts for about two weeks, assuming a daily dosing schedule. I don't have any problems dissolving enough KNO3 or any other of my ferts when I use this type bottle. http://www.greenleafaquariums.com/aquarium-fertilizers-supplements/dispenser-16oz.html is one source for these.


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## Sterling919 (Jan 19, 2008)

I like the look of that too...cool idea. What I don't understand in that calculator is the selections from that drop down menu. If offers you Nitrate from KNO3 and then Potassium from KNO3. Both have different PPM target amounts and both show different PPM per ML for dosing mixed at the same amount of water. So how do get both target levels right when you are dosing two different amounts of the same product?

That is what confuses me. How do you check to see if there is enough KNO3 in the water? By testing for Nitrates? If so, then I assume since the target level in the calculator is 5ppm then you'd want your Nitrates to show 5ppm's on the test kit, right?

I assume for KH2PO4 then you'd have to buy a test kit for that if your current test kit isn't equipped with such a test, right? And then how do you know if you've got enough CSM+B in the tank...how do you test for micro's/trace elements? Another confusing thing to me.

I know using the EI method is suppose to do away with test kits so to speak. And it seems the more I read the more people just think a 50% water change in a planted tank isn't a bad idea period. I assume doing water changes is for putting trace elements back into the water among other reasons. But then how do you know to dose or not to dose the Plantex?

What I'm doing right now is 1/4 teaspoon of KNO3. Or as close to that as I can figure on my little medicine cup since it only goes down to 1/2 teaspoon, I just do about halfway to that mark. Then in the EI guide is shows that KH2PO4 and CSM+B is 5ml or 1/8th teaspoon. How can 5ml be 1/8th teaspoon? I put KH2PO4 and CSM+B at 5ml on the medicine cup...dumped everything dry into the tank. I suppose I've screwed up??


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## Left C (Jun 14, 2005)

Sterling919 said:


> Ok, somebody help me here...
> 
> Chuck's calculator says you need to mix 11 teaspoons into 250ml of water to get a solution that will yield 1ppm @ 1 ml. The target level of KNO3 is 5ppm for a 40g tank. So you'd dose 5ml at a time to get to the 5ppm target, right?
> 
> ...


The following two charts might be helpful for knowing the solubility in water for some compounds and much more info:
http://ca.geocities.com/[email protected]/Percent.of.mass.htm
http://ca.geocities.com/[email protected]/grams.per.100.litre.per.1.ppm.htm

They're from here.


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## ray-the-pilot (May 14, 2008)

*I think you have a problem*



Sterling919 said:


> I
> 
> How can 5ml be 1/8th teaspoon?


I have the same question. The last time I checked, 1 tsp = 5 ml.; so, 1/8 tsp = 0.625 ml.

I'd do a couple of 50% water changes on your tank and hope for the best.


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