Chlorine Experiment and apologies!

First of all I would like to apologise for the lack of posts recently, I ran into some Internet troubles at home and I don't have enough time to update whilst I'm in school.

Now that that's out the way I figured I could jump straight back into the swing of things and give you guys a rundown / update on my 'Chlorine replacement' experiment.

Thats a pretty nice pool

The general Idea behind the experiment is to find a suitable, cost effective alternative to using chlorine to cleanse pool water, so far I am using various fruit and veg extracts to test against my homemade chlorine solution.

I will test the effectiveness of each solution by placing small anti-bacterial disks that will have each of my prototype solutions added to them, then, over the course of a week I will measure the diameter of dead cells and record my results accordingly, simple enough, right?

This whole process has been a bit of a nightmare since the start in terms of getting hold of chlorinated water, on paper its simple, get pool water sample from local swimming baths, make up fruit and veg extracts, plate up my bacteria, add anti-microbial disks, write up, bish bash bosh, done.

However I ran into my first problem when attempting to acquire a sample of pool water, to go into a public pool and collect a sample of water wouldn't have done the experiment much good in terms of accuracy due to it being old and effectively contaminated, so next I was put into contact with a student who's next door neighbour works at a public bath house, the student very kindly offered to ask her neighbour on my behalf for a falcon tube or two filled with water, however this idea was quickly shunned as we only had the neighbours word of what the contents of each tube was, so this wasn't viable, lastly after many talks on a course of action we came to the conclusion that the best way to get some chlorinated water would be to make it ourselves, so the school very kindly ordered me some chlorine tablets off of the Internet which arrived today.

Now, with the tablets here all I had to do was make up a solution befitting a 1 litre bottle from a 20g tablet that is made to chlorinate 4500 litres of water, so, Being the maths genius that I'm not, I divided 20g by 4500 which gave me a value of 0.004g, so this was my 'endgame' value, the next part would be diluting down to the desired concentration.

I achieved this by first making up a 20g solution in 1 litre of water, then once the tablet was as dissolved as much as possible (thanks to the help of Jack Webster, a member of Greenland who kindly helped crush and mix the tablet whilst I was attending a lesson), I took a 1000 micro-litre Gilson and added 1 ml (1000 micro-litres) of this concentration into 1 litre of pure, deionised water, this effectively diluted down the chlorine content of water from 20g to 0.0200g which was a large amount to be fair, but not quite what I was after.

It was at this stage that I realised that if I were to dilute down using the same amount as previously (adding 1 ml to another 1 litre of pure water) I would have a net value of 0.00002g of chlorine in the water, far too low, to get the golden number of 0.004g I would have to divide 0.02g by 10 and double it, so this meant that i would need 200ml of my current solution in 1 litre of pure water.

Now as much as I love using the Gilson to pipette, pipetting anything 200 time is fairly tedious, therefore I decided upon the use of the trusty measuring cylinder, after completing this I had finally finished making my chlorinated water solution, a mini-celebration is probably an order now!

Next step is to get my old friend Staphylococcus Epidermis to grow better, and it's particular about the agar it likes and doesn't like, hopefully this will go as planned and I'll have some results to show for the work that's gone into this whole project.