[RESOLVED] Help me figure out this liquid dilution problem

[MartinLiss]

I have a semi-automatic watering system for a house plant or two that has a 2-cup reservoir and the reservoir has developed some algae that I would like to get rid of. I have an algicide that the directions say should be used in a 1 teaspoon per 50 gallons of water proportion. I would like to make up a pint of diluted algicide/water mixture such that 1 teaspoon of the mixture would be the proper amount to add to the two cups of water. It makes my head hurt to think about it. Can someone help?

[mendhak]

A gallon is 16 cups, so going by 1 teaspoon per 50 gallons, you get 1 teaspon per 800 cups. Or, 1/800 teaspoons per cup.

And a pint is 2 cups, so the answer is 1/400th of a teaspoon per pint.

Good luck separating the granules from each other.

[MartinLiss]

I'm not sure your answer is what I want. I don't want the pint to be at the 1 tsp/50 gal proportion but rather some proportion so that when I add 1 teaspoon of the diluted mixture to the 2-cup reservoir, the reservoir will be at the proper proportion.

[timeshifter]

Mend's answer stands. Simple proportions.

[MartinLiss]

I don't see how. Given that 50 gallons = 400 pints and 400 x 1/400 tsp is 1 teaspoon, that's the same dilution that the directions suggest. I believe I need a more concentrated solution so that it 1 tsp of it when added to 2 cups of water the result will be the suggestion dilution.

[System_Error]

For it to be proportional, you would have to consider the two cups in the reservoir making a total of 4 cups. The solution should be 1/200th teaspoon.

[Shaggy Hiker]

How many teaspoons in a cup?

You need that for a couple steps. Figure out the concentration in the stock solution (not 1/800, you need 1/(teaspons in 50 gal)). Call this StockC

Then figure out the dilution factor of the reservoir (1 tsp/ 2c * #tsp in a c). Call this ResC.

It's mighty late, but I think the dilution factor you need for your reservoir is StockC/ResC. You then have to come up with a tsp/unit that matches that dilution factor.

[zaza]

I have a semi-automatic watering system for a house plant or two that has a 2-cup reservoir and the reservoir has developed some algae that I would like to get rid of. I have an algicide that the directions say should be used in a 1 teaspoon per 50 gallons of water proportion. I would like to make up a pint of diluted algicide/water mixture such that 1 teaspoon of the mixture would be the proper amount to add to the two cups of water. It makes my head hurt to think about it. Can someone help?

Let's go through it step by step.

There are 16 cups in a gallon, therefore your reservoir holds 1/8 of a gallon. You need 1 teaspoon of algicide per 50 gallons, therefore for 1/8 of a gallon you need 1/400 of a teaspoon.

Therefore you want to make a mixture such that 1 teaspoon of it contains 1/400 of a teaspoon of algicide. By volume, 1 pint is 96 teaspoons, each of which must contain 1/400 of a teaspoon of algicide.

Therefore in your pint of mixture you want 96/400 teaspoons of algicide, or just shy of 1/4 of a teaspoon.




Note: Actually, this isn't mathematically quite correct. To be absolutely precise, we should have accounted for the fact that your teaspoon of mixture is part of the two cup reservoir, and that the volume of the algicide contributes to the volume of the mixture. However, we have considered these to be small by comparison to the volumes of water.

[MartinLiss]

Let's go through it step by step.

There are 16 cups in a gallon, therefore your reservoir holds 1/8 of a gallon. You need 1 teaspoon of algicide per 50 gallons, therefore for 1/8 of a gallon you need 1/400 of a teaspoon.

Therefore you want to make a mixture such that 1 teaspoon of it contains 1/400 of a teaspoon of algicide. By volume, 1 pint is 96 teaspoons, each of which must contain 1/400 of a teaspoon of algicide.

Therefore in your pint of mixture you want 96/400 teaspoons of algicide, or just shy of 1/4 of a teaspoon.




Note: Actually, this isn't mathematically quite correct. To be absolutely precise, we should have accounted for the fact that your teaspoon of mixture is part of the two cup reservoir, and that the volume of the algicide contributes to the volume of the mixture. However, we have considered these to be small by comparison to the volumes of water.

Thank you.

[MartinLiss]

I decided to delete a few posts from this thread since they were off-topic.

[dclamp]

I decided to delete a few posts from this thread since they were off-topic.

Marty:

If you have not noticed, you posted your question in the Chit Chat / General Discussion Forum. Every ccgd regular knows if you are going to ask a some what technical post in here, you should alert the members that it is serious by placing [SERIOUS] in the title.

Yes, i have read Brads post about the serious tag, but we still have not taken that into concideration. If you wanted serious answers you should have put the [SERIOUS] tag.

Regards,
dclamp

[si_the_geek]

dclamp et al, the rules of this site are not up to you - the 'serious tag' is never required, and off-topic posts in serious threads are not acceptable (see timeshifter's thread for more details).

The General Discussion / Chit Chat forum is for any topics which are not suitable for the other forums here - not just for random chat.

If you have further comments about this, please post in timeshifter's thread.

[dclamp]

ok thanks

[MartinLiss]

And if there had been a more appropriate place for it I'd have posted in a different forum.

[dclamp]

Maths Forum

[MartinLiss]

Moved from Chit Chat.