GobyMaster11276
Fish Crazy
So I have a 70l well planted (if not over) tank with two bettas (divided). I have two corner sponge filters, and do about 40-50% water changes weekly. Last week, when testing the water, I discovered the nitrates were alarmingly high (at the very top), even though the week before they had only been just above 0ppm. I did a 60% w/c. This week, I tested again and it was back at the top. I did a 50% w/c, then about a hour later I retested and it is still at 160ppm. How is this even possible? I retested twice just to make sure it was correct. Thanks in advance.