Very good surface agitation and no fish breathing heavy.What about oxygenation? You have any fish breathing hard? No glass top and plenty of surface agitation?
Will get a photo later, GHA is substantially subsided.You mentioned in an earlier post you have GHA. Is that still a problem?
Overall do you have enough food? Snake won’t go to GHA while the urchin will (usually). An urchin will outcompete snails. Maybe a picture of your tank? Also what temperature is the tank?
