by Stephen Bellamy on 26/10/2018Have worked well in the past. Does keep the chemical balance right for about 1 1/2 to 2 weeks whilst not being used / away.
by Karl Quirk on 04/08/2018
by peter leonard on 13/07/2018
by Chrs Brown on 13/06/2018
by Pravin Mistry on 15/07/2017Easy and convenient
by rosemarie belcher on 16/10/2012