Question about Intex Purespa Bubble Massage

I use chlorine tablets and check the pH value and chlorine dosage daily. By cleaning the filter every day and leaving it running for 2 to 4 hours a day, the water keeps particularly well for 6 to 8 weeks. Unfortunately, hair gels and sun creams contaminate the water a lot...
Without chlorine, the water lasts me three days and I get impurities and algae.