The bleach i got was from a pool store. Something akin to this: http://www.stuff4pools.co.uk/acatalo...les.html#a4070

This is the main kit i've been using (http://store.cascadepools.co.uk/pool...m=shoppingfeed).

In addition yesterday I tested with strips like this (http://www.amazon.co.uk/AquaChek-Fre...4922741&sr=8-4). I knoww they're unreliable but its the best i've giot at the minute.

Last night (before I put the chlorine in) these were the respective readings from the two kits:

Total Alkalinity: 100 (AquaChek)
Stabalizer/CYA: 40 (AquaChek)
pH: 7.6 (Aquacheck & Palin kit)

This morning I used an AquChek strip and the Chlorine part went a nice deep purple colour. Unfortunately i've run out of DPD No1 tabs (only got DPD No3) so couldn't get a reading from them too - i'l pick some more up tomorrow.

Does this help the diagnosis?