Recent content by banker

I HAVE A COMMUNITY TANK OF ABOUT 14 MONTHS IN AGE IT HOLDS APPROX 40 FISH MAINLY QUITE SMALL. IT IS UNDER GRAVEL FILTER 5 PLANTS AND 3 ROCKS. I CHANGE 20 PER CENT OF THE WATER EVERY 2 WEEKS AND FEED ONCE A DAY. MY PROBLEM IS THE PH KEEPS DROPPING DOWN TO ABOUT 5 THIS DOES NOT SEEM TO AFFECT MOST...