water purfification tested for bacteria

[Saym14]

[cryoguy]

Thanks for the post! I made my own water filter out of PVC pipe and was wondering how it will do. Where did you get the test strips?

[Saym14]

Thanks for the post! I made my own water filter out of PVC pipe and was wondering how it will do. Where did you get the test strips?

http://www.sciencefaircenterwater.com/SFCWaterIntroTxt1.html

[echo1]

I'm a licensed pasteurizer, and at sea level, water doesn't have to boil to kill bacteria. 180 degrees kills it. PAX

[Saym14]

180 degrees kills it. PAX

not all of it according to our tests. we are at 900 feet.

[meaty-btz]

not all of it according to our tests. we are at 900 feet.

Did you ensure that you were not transfering bacteria into your sample during testing? Also, how long did you boil the water? Certain blue/green types can withstand caldara temps and would be immune to boiling for any length of time.

Doing this kind of testing in a scientific way requires a great deal of effort to prevent cross-contamination. Especially in the home where bactiera are often present in the air itself. Might scare you to run that test on some air-samples from inside the home.

The solar methods effectiveness can be linked not to heat but time and also UV radiation, which by far is the most effective way to kill microbes. A further study would be recomended by having water exposed to sun on a black surface vs a handheld high intensity UV source (usually used in UV filtration/purification). Chances are the UV method would result in the water being "clean".

Water saftey of course goes beyond bacteria and microbes (you do not want an amoeba in your stomach....) don't forget about removing other contaminants. If I was building a bugout filter system, I would build a portable UV source (easy) + comercial partical/metal filter.

[echo1]

not all of it according to our tests. we are at 900 feet.

You better contact Cal. Dept. of Ag. and have them adjust the study guide and licensing criteria. Actually, it's time & temperature for pasteurization. Our in house standard was 185 degrees for 90 seconds, which exceeded the state limits by 5 degrees and 10 seconds (or somehting like that). PAX

[SKSer]

My daughter tested 4 treatment methods for lake water as part of a school science experiment.
1) Boil for 4 minutes
2) Iodine tables for camping
3) Homemade filter (cloth, sand, and charcoal)
4) And solar – put in PET water bottle on black surface for 8 hours in direct hot sun.

Samples were then tested with bacteria test strips. The Solar method actually produced the best results, almost no bacteria growth. Boiling and then iodine were next. The filter was the same as the lake water for bacteria, but I think it would make a good pre-filter before doing one of the other methods.
Most books recommend boiling and then adding 16 drops of bleach per gallon. Now I know why.

The homemade filter is designed to get as much of the toxins out as possible, it does little to nothing for bacteria.

It is actually pretty difficult to do these tests unless you know what you are doing. Bacteria is extremely easy to pick up. First you must make sure you have completely sterile test bottles, then If your daughter touched the bottle on the inside or even the inside of the cap, you could have cross contamination. Cross contamination could also happen from several other scenarios, a sneeze, a cough, a flake of dead skin falling into the sample etc. which is why you want at least 3 seperate, completely sterilized test bottles for each test just in case.

With water there are two main things you are trying to get rid of, Toxins that will poison you and Bacteria that causes water born Illnesses. Getting rid of bad bacteria is the most important, toxins you really only need to worry about if you are going to be drinking from the same source of water for a long time, unless that source for some reason or another has an exteremely high level of toxins in it.

If you were in a SHTF scenario and you needed to clean a perticular source of water you would want to filter it with your homemade filter first, then bring it to a rolling boil for 5 minutes. If you boiled it then filtered it, chances are you could pick up more bacteria from your homemade filter.

Also im not sure what types of bacteria your tests were saying were present in the water, but not all bacteria is bad. That brings us to the difference of disinfection vs sterilization. With your regular Tap water, it is chlorinated, which is disinfection, which is killing the bad bacteria and leaving the good. Boiling is sterilization which is the killing of all bacteria.

if you are ever worried about disinfecting water, pick up a few of these, its cheap at walmart in the pool supply:

http://www.archchemicals.com/Fed/HTH/PoolCare/shockstep.htm

one tiny pinch of this would disinfect a 50 gallon drum of water.

[Saym14]

boiled for 6 minutes. the test showed very littel bact for boiling, but there was some. its true it could have come fromthe air during transfer to the test strips.

[DTOM CA!]

The homemade filter is designed to get as much of the toxins out as possible, it does little to nothing for bacteria.

It is actually pretty difficult to do these tests unless you know what you are doing. Bacteria is extremely easy to pick up. First you must make sure you have completely sterile test bottles, then If your daughter touched the bottle on the inside or even the inside of the cap, you could have cross contamination. Cross contamination could also happen from several other scenarios, a sneeze, a cough, a flake of dead skin falling into the sample etc. which is why you want at least 3 seperate, completely sterilized test bottles for each test just in case.

With water there are two main things you are trying to get rid of, Toxins that will poison you and Bacteria that causes water born Illnesses. Getting rid of bad bacteria is the most important, toxins you really only need to worry about if you are going to be drinking from the same source of water for a long time, unless that source for some reason or another has an exteremely high level of toxins in it.

If you were in a SHTF scenario and you needed to clean a perticular source of water you would want to filter it with your homemade filter first, then bring it to a rolling boil for 5 minutes. If you boiled it then filtered it, chances are you could pick up more bacteria from your homemade filter.

Also im not sure what types of bacteria your tests were saying were present in the water, but not all bacteria is bad. That brings us to the difference of disinfection vs sterilization. With your regular Tap water, it is chlorinated, which is disinfection, which is killing the bad bacteria and leaving the good. Boiling is sterilization which is the killing of all bacteria.

if you are ever worried about disinfecting water, pick up a few of these, its cheap at walmart in the pool supply:

http://www.archchemicals.com/Fed/HTH/PoolCare/shockstep.htm

one tiny pinch of this would disinfect a 50 gallon drum of water.

SKSer,
How do you know so much about water purification ? Do you work in that industry.

[Exile Machine]

Curious why the choice of homemade filter and not one of the commercially-available camping/backpacking filters like a Katadyn?

[SKSer]

SKSer,
How do you know so much about water purification ? Do you work in that industry.

Yea, I work for a water company, and I have a Grade 2 Water Distribution License.

[Chaparral]

It'd be pretty easy to do the testing using aseptic technique with a burner, innoculation loop and nutrient plates or tubes. Pretty accurate results with minimal contamination can be obtained. The materials needed are simple and low tech. I could teach this at a skills meeting. We could test water repeatedly from a number of different sources including surface fresh water in urbanized areas, roof runoff, mountain streams etc.

[Saym14]

after seeing these results - If I were going to drink lake water I would
1) pre-filter
2) boil
3) add cholrine or bleach

[DTOM CA!]

after seeing these results - If I were going to drink lake water I would
1) pre-filter
2) boil
3) add cholrine or bleach

Why not add sun or uv light to top it off.