Ok. Well adding DE to it will help it filter better but you will probably need to back wash more often.

You need to perform the shock process. And because you had metal staining problems get the pH lowered before you start the shock process as you won't be able to accurately measure the pH.

Thanks but I have had the pool at shock for five days now, still murky and still has a green hue although not as green as before.

Do I maintain a higher shock for longer or just be patient?

Also, can anyone tell me what is so bad about a floculant versus using DE? I would like to stick to the BBB method but things are feeling very slow.

Here are the readings I got from the pool shop today:

CYA - 40
FC - 10 (at least. They use a Palin test 25? that can only detect up to 5ppm I believe. The guy said he suspected ig he were to dialute it would be around 10 ppm)
TDS - 400
pH - 7.8 (I have put in some pH down and will test again tomorrow)
TA - 115 (as above)
CH - 126

Thanks for the support - I'll get there eventually

If the cya is 40 ppm the shock level is 16 ppm. Sounds like the pool store isn't really sure where the fc level is, seems like it is prob to low. If the cya is higher than 40 ppm it's really too low.

It looks like you're not keeping the shock level high enough for your CYA. You can dilute the sample 2 or 3 parts and have them test it again but there's really no substitute for a good test kit. I assume you're not in North America so the Palintest 315C would be a good kit for you.

BBB is about understanding how pool chemistry works and learning to take control of the pool maintenance using simple and affordable chemicals. The first and most important step to being able to self manage your pool is to have a good test kit (as was previously suggested in this thread on 12/6). You can not effectively shock your pool per the BBB method without a good test kit. BBB will work and be much simpler once you have a proper test kit.

The flocculent will not clear algae from the water. After all the algae is dead and the water is cloudy/clear then you may attempt to use a flocculent but there are no guarantees that it will improve the water clarity. First you need to kill all the algae.

Are you still using liquid chlorine? You can use The Pool Calculator to determine how much chlorine to add to reach shock level for your pool. Once you reach shock level you must keep the pool at shock level until all the algae is dead. That means you may need to add more chlorine several times a day, since chlorine levels drop as the algae is killed. You will know the shock process is complete when the chlorine level drops only 1ppm or less overnight. Since you do not have a test kit at home, it will be harder for you to know when you are at shock level and when the shock process is complete. A good quality test kit is an investment in your pool, and using and understanding the test results will prevent many of the issues you have now from recurring.

While you are relying on the pool store to test the water, use distilled water to dilute the pool samples before you bring it in for testing.

Hi all.

Thank you for the advice. I have upped my chlorine dose to around 16-200ppm (I'm diluting my water with 75% distilled water to give an indication of chlorine levels in the pool) A dramatic difference, after 3 days the pool is now a white/ grey blue. I obviously wasn't using enough liquid chlorine. I will keep going for a few more days but slowly ease off the chlorine levels until it stabilizes overnight.

I now have a lot of dead algae to filter out. It is getting clearer by the day but very slowly - I can just see the 3rd step now. The filter is running 24/7 and backwashing every morning. I'm going to give it a few more days and then give a small amount of DE a try.

It does seem that my original problem of iron staining has gone, and with the dumping of 75% of my water a lot of inherited and persistent problems have now been eradicated

I would love to suggest a sticky or an adendum to the 'shocking your pool' article that covers high chlorine dosing for various problems. As most test kits don't go over 5ppm and a lot of missguided information just refers to 'shock dose' and not a particular level of shock dose it might be nice to condense this all into one article. The answers are on the forum but one has to trawl around and figure it out (unless I'm missing an obvious post)

The support and input has been invaluable so far from various contributors - thank you. I have learned so much. I hope to post a picture of my pool when it is crystal clear.

WRT (nobody performing) testing for iron and copper: check with aquarium supplies/ shops instead of pool supply, those are common water tests. Since you don't know where the metal content in the previous water came from, you may want to test now and test again in a couple months to see if the concentration goes up (if the problem is still there).

Hi koos and welcome to TFP!
These are in the Pool School link...
This is a simple chart to keep it from being over complicated.
pool-school/chlorine_cya_chart_shock
This is the pool calculator link here...
pool-school/pool_calculator
This link refers to the shocking process...
pool-school/shocking_your_pool

A FAS-DPD chlorine tester is a must as your finding out, it's unfortunate that products we can get easily, is much harder for you.
Your on your way now that your starting to understand what we are teaching and helping you to a TROUBLE FREE POOL!
We all have been lost with our pools, but with this wonderful website, being persistent with learning and reading here comes the understanding pool chemistry. Good reading here:
pool-school/pool_water_chemistry

This link has become one of my favorites for me...without this forum I wouldn't have a pool as I was at my whits end with getting pool stored and I'm thankful for what I have been able to learn, understand and REALLY now ENJOY our family pool! I suffer from Poolsparklyitits!
click-here-to-become-a-troublefreepool-com-supporter-t183.html

Chuck