what?

Found this snail/whelk thing in my tank. I didn't add it. Is it good/bad/indifferent??

So usually my ORP sits in the mid 300's for ORP but have recently noticed these sudden "dips." They are not necessarily at the same time every day and don't correspond to a dosing time. See below: All fish are accounted for and water chemistry raises no alarms. ORP is very hard for me to...

It dawned on me today, as I was doing some preventative maintenance in my sump, that your glass can be spotless on the inside of the aquarium but if the outside is dirty, its all for naught. Unfortunately he outside of your aquarium is seemingly an extremely overlooked topic - but as i looked...