poppy

There is no indication I can find on the shelf life for these systems. I have seen posts saying you should replace every 12 months but no detail or data to back up the recommendation. I use my LFS. Test my water with my kit, note the results then take a water sample to my LFS. If their results match mine I figure the home kit is still accurate.

I have a 6' 300 litre tank with mainly peacocks. Originally I was running an Aqua One Nautilus 1100 and a Sunsun HW303A. Regular water changes and replacement of the filter wool kept the tank clean. After the Nautilus developed a leak (o-ring) I replaced it with a Sunsun HW-303B with a UV light. The UV was promoted as the next step or additional water purification system. I added the media from the Nautilus and what was needed from the supplied Sunsun media to fill the trays. Within a week I had an outbreak of stringy green algae. The HW-303A and HW-303B are rated at 1400L/H so it would at worst be turning the water over three times per hour. I was under the impression the UV would provide extra protection from algae blooms like this. I have since turned off the UV but I am still having problems with algae in the tank. The walls of the tank seem to get a heavier lining of algae than I have ever had before. This week I have deep vacuumed the substrate. I didn't clean the filters as they still appear to have good flow. I have now removed all of the rocks to dry in the sun and kill off the algae. When cleaning filters I fill a 30 litre tub with water siphoned from the aquarium. The sponges and media are rinsed in the tub and filter wool is replaced. Only one filter is cleaned at a time. Water is tested regularly and show no adverse results. To verify the accuracy of my water tests I have the water tested at my LFS evey 6 - 8 months. They always come back with the same results I get. What am I missing or doing wrong.