Make Crystal Clear Ice!




in this instructable I will show you how to make crystal cear ice without any special equipment! it is super easy! you will be surprised!

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Step 1: Use Filtered Water!

the filtered water is much more pure and clean!
one of the things that causes the cloudiness of the ice is dust and
extra minerals in the water - the filtered water is much better for our clear ice!

Step 2: The Main Step! - Boiling the Water!

this is very simple but very effective!
- Boil the water , and than let it cool.
- after it is cool , boil the water again!
- this is it! you are done !
explanation :
the double boiling eliminates dissolved air in the water and decomposes minerals in the water ! dissolved air + minerals +dust
are the causing of the cloudy look!

Step 3: Results !

this is the difference between regular ice (cloudy) and the crystal clear ice- after following the process!

I hope you find this instructable useful and fun!

enjoy your crystal clear ice!

1 Person Made This Project!


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205 Discussions


12 years ago on Introduction

when you freeze hot/warm water, it will freeze more quickly as regular cold water

19 replies

Reply 9 years ago on Introduction

Let's do a "thought experiment". Start with two totally identical freezers. (This is a thought experiment, so they can be totally identical.) Take two identical containers. Put a sample of room temperature (let's say 70 deg F) water in one, and an equal amount of hotter (let's say 90 deg F) water in the other. Now put each of the containers in its own identical freezer. After some period of time the 90 deg water will have cooled down to 70 deg F. But in that same period of time the water that started at 70 deg F will have also cooled down. No matter what the period of time the water that started out hotter will ALWAYS BE PLAYING CATCH UP.  So it cannot ever freeze faster than the cold water.


Reply 2 years ago

I read a good bit of this thread and saw how many people could be really insulting to each other, and I hope I do not come across so. The foundation of science is not education and expertise or arguing and definately not insults although those abound, it is experimentation, and full of unexpected results. One of the most unexpected I have seen is throwing a pan full of boiling hot water into sub-zero freezing air and getting an apparently instant conversion into what looks like snow but is probably tiny ice. Plenty of those on youtube. The same test with cold water and you get cold water. I have no idea why, but I expect it has to do with heat of vaporization and some magic occurring near the boiling point. (No not really magic). Someone cleverer than I will probably some day do some actual experiments and explain this apparent contradiction.


Reply 2 years ago

Oh, I forgot to thank the original poster of this fine suggestion on making clear ice. Thank you, great idea.


Reply 8 years ago on Introduction

The hot water is hotter and it will need to cool down more, but it still cools down faster. It's possible that they will both be ready at the same time


Reply 8 years ago on Introduction

OK, for the sake of argument, let's assume that hot water reaches 0 C sooner than the same amount of cold water. (This eliminates having to deal with the non-linearity of crystal formation.)

so if TH is the length of time for the hot water to reach 0 C, and TC is the length of time for the cold water to reach 0 C, and DT is the difference between those times, then

TC > TH ________because the cold water takes longer to reach 0 C, and

DT = TC - TH ____DT is how much more time it takes for the cold water to reach 0 C than it took for the hot water.

But since the hot water starts out at a higher temperature than the cold water did, the hot water will at some point in its cooling reach the temperature that the cold water started at. Let's call this time D. From there, the amount of time for the hot water to reach 0 C should be equal to TC, the amount of time for the cold water to reach 0 C. At this point in time the hot water has cooled to exactly the temperature that the cold water started at so from here it should take that same amount of time to reach 0 C.

Now we can represent the amount of time for the hot water to reach 0 C as:

TH = D + TC ______Because the hot water MUST at some time go through the temperature that the cold water started at.

Now substitute the right hand side of the second equation for TH in the first equation.

DT = TC - TH

DT = TC -(D + TC)

DT = TC -D -TC

DT = -D

But DT and D CANNOT be the negative of each other because they are both positive numbers representing durations.

So TC cannot be larger than TH.

Furthermore, TC must be larger than TH, because if they were ever equal that would mean that D were 0, i.e., at some pair of hot and cold temperatures, the hot water would have to cool INSTANTANEOUSLY to the lower temperature.


Reply 8 years ago on Introduction

Call me in the winter when your hot water lines burst before the cold ones . Sorry no fancy formulas just plain simple reality . I am a 3rd degree black belt in plumbing waterology have phd in turdherding. Ask any pumber or heating guy and he will tell you the same thing only in plain english . Hot water will freeze quicker than cold .


Reply 4 years ago

Hot pipes freeze fast in cold because of flow. there use much. Less than coldwater pipe site for hours without use hot water flow.just think when go get glass of water in nite or flush. That coldwater. hot water pipes calls you get let guess In basement is where they fail most homes with basement are colder by 10 - 15 deg and in a drift and u get to make $$$


Reply 8 years ago on Introduction

LOL. Good thing I spent my career doing simple things instead of plumbing.

The next time you see a picture taken by the Hubble Space Telescope, THAT was the kind of thing I did for a living until I retired. (And NO, I was not involved with the flawed optics. I worked on the spacecraft itself, not the payload.)


TH = D + TC ______Because the hot water MUST at some time go through the temperature that the cold water started at.

This step contains the logical leap. Yes, the hot water temp MUST at some point be equal to the initial cold water temp, but those are temperatures. It's an assumption to say that the rates of temperature change will also be equal at that point.


If you are going to assert that the rates of change will be different, the onus is on you to provide a reason for that to be the case.


I'm not asserting that the rates of change will be different. I really don't know. I'm asserting that it's an assumption to conclude they WILL be the same merely because the temperatures will be the same.


My assumption is based on the foundation of scientific inquiry. I.e., that two identical systems will consistently behave in the same fashion. That's why different groups will repeat experiments done by others to verify that the same result is obtained.

If you think that my assumption is unwarranted, the onus is on you to provide some reason why you think that is the case.

I also assume that the force of gravity will remain relatively constant throughout the course of my day (subject to the known variations due to irregularities in the distribution of the Earth's mass).

Would you also question that assumption? If so, why? If not, why do you question my assumption that two identical pans of water in identical freezers will freeze at the same time?

i'm guessing you didn't take chemistry when you posted this. actually, water that is 90 degrees has more energy than water at 70 degrees. for the most part, you see that this follows logic and common sense. the freezer, let's say, is at 0 degrees, just for simplicity.

now, think about diffusion, more specifically entorpy: movement of heat from a higher "concentration" source to a lower concentration source. this movement can be facilitated/sped up by larger differences in concentration.

since water at 90 degrees has a larger energy difference with a 0 degree environment than water at 70 degrees with a 0 degree environment, the water at 90 degrees will actually freeze faster, because the heat in the 90 degree water will diffuse/escape from the water much more quickly as a result of entropy.


Reply 5 years ago on Introduction

Sorry Chemist123 - I know this comment is a little late but I just performed the experiment, MythBustsers style, and your interpretation of "entorpy" (which I am assuming is supposed to be entropy, the description of the universal preference for disorder over order) proves false. I filled two trays of ice, both trays from the same manufacturer (Rubbermaid), one tray with 60 degree water, one tray with 100 degree water (+/-5 according to my laser thermometer) both side by side on the same tray of my freezer (0 degrees according to the thermometer) and, believe it or not, the "cold" tray of water froze first (at 30 minutes it started to freeze over, with an average surface temp of 27 degrees) while the "hot" tray had an average surface temp of 37 degrees.

Oh, and I boiled both samples of water for 10-20 minutes - the cold one I stuck in the fridge and stirred with glass drink mixer on occasion until the average temp cooled to 60, while the "hot" water I let cool in a covered pot on the stove until the cool one was 60.

But who cares - I'm just some idiot who was dumb enough to be fooled by internet tomfoolery. There may be some combo of temps that can accomplish the described effect, but the required temps would have to be very narrow as to make the effect unnoticeable :

The water at 90 will certainly be cooling off faster AT FIRST. But at some point the 90 degree water must be at 70 degrees.

Are you claiming that once the 90 degree water reaches 70, that it will then cool faster than water that simply started at 70?

Thought experiment:
Put 90 degree water in one freezer. Wait until it reaches 70. At that instant, you put some 70 degree water in another freezer.

Now you have two freezers, each with an identical container of 70 degree water.

What happens now? Why/how would the water in one freezer cool faster?

In my response to zmarsh below I attempted to encapsulate the above argument in a rigorous fashion. If there's an error in the math or logic, please point it out to me.

(And BTW, I was a double major math-chem until midway in my junior year at which time I realized that math was the place for me.)

LOL.Good thing you switched to math. Hot water can freeze faster than colder water under certain conditions. It is called the Mpemba Effect. Rather than write a dissertation here just take the time to Google it. It will enlighten your mind.

I have Googled it, and I have noted that every attempt to seriously defend it includes a lot of verbal "hand waving". The Wikipedia article says it best "There are no reliable sources that indicate exactly how to demonstrate the effect and under exactly what conditions it occurs."

If you're willing to believe in something like that, maybe we should talk about a bridge that I have for sale.