I've had three J. marlieri juveniles for about half a year now in a lightly planted 20 gallon tank. They've only grown from about 3 to 4.5-5 cm and are very inactive. Mostly hang out in the rockwork or sit on the substrate all day. Is that normal or should I be worried?
I used beach sand, rinsed it many, many times, boiled and baked it to sterilize. It contains tiny shell pieces so it raises the pH slightly. Recently I started to wonder whether it might contain heavy metals though and whether that might account for the poor growth. Or is tank size or water quality the more likely culprit? I used to do water changes once a week, then increased to two after which they seemed to grow a bit better. They poop so much though that I feel even twice a week isn't ideal.
I used beach sand, rinsed it many, many times, boiled and baked it to sterilize. It contains tiny shell pieces so it raises the pH slightly. Recently I started to wonder whether it might contain heavy metals though and whether that might account for the poor growth. Or is tank size or water quality the more likely culprit? I used to do water changes once a week, then increased to two after which they seemed to grow a bit better. They poop so much though that I feel even twice a week isn't ideal.
