Yes. I got sand.But it looks like a lot of water in that tank compared to rock. You got sand? What’s NITRITE at?
Just did a nitrite test. It's salifert and close to expiration date, so not sure it can be trusted. Shows 0.1ppm, the highest I've seen yet.
Nitrate looked very high earlier, which is a bit odd as not that much ammonia have been present?