I learned quickly that diamond gobies love to jump out of tanks and can fit through almost any opening
Depending on how big it is, you can probably save it. You may have to start the tank over or at the minimum drain the water below that spot but I’m pretty sure you can buy glass repair stuff for aquariums. Go on reef2reef forum if you want ask those folks. Even though they are mostly saltwater, there’s some extremely knowledgeable folks on there. I’m talking people that built their own thousand+ gallon tanks. They could probably provide some good advice and info.
Worst case I still don’t think you’re screwed. Looks small enough it may be able to be repaired and only have to drain the rank below it.
tank is cycled, 0 nitrate nitrite and ammonia. hardness is still a little high - working on that. have taiwan lilies floating atop till they get better roots, 3 handfuls of red root floaters, an anubias barteri, 1 crypt parva that I split into three, 2 Indian ferns, giant hairgrass, 2 rotala indica, and a vallisnaria spiralis. Haven't had any totally melt, though the crypts have algae on the leaves that I didn't clean off until recently. they're so-so. and I unfortunately have to ring off the red root floaters as they haven't done well when agitated by the filter. regrets: not going with fluval substrate. it's hard to get some of the plants down into the caribsea eco-complete substrate I have; not glueing some of the plants onto the rocks e.g., the anubias; and not aquascaping dry beforehand - a lot of it has been on the go. YouTubers make it look relatively easy to create robust aquascape. I also need to stop seeing it as a chemistry project and let it settle in. currently have 5 amano shrimp, 2 mystery snails, and 2 nerite snails. the latter don't move all that much. will happily go the route of wood and less rocky next time as this tank is a conglomerate of randomness. more ground cover plants will help. Spoiler
have 6 panda corys that have acclimated well Spoiler and 8 blue eye gold neon tetras Spoiler centerpiece thoughts are: two honey gouramis; another schooling fish; bamboo shrimp; or a few otos (6 months down the road once it has plenty of biofilm and algae). not a lot of other fish for a 20 gallon that are shrimp safe. maybe danios/rasboras (to fill the top of the tank) or barbs?
Also you can still glue stuff to rocks. They have glue that is water soluble and non toxic. I glued rocks together, coral to rocks, etc well after my tank was established.
My old aquarium guy is really trying to get me to find room in my apartment for one. Told me he’d cut me a deal on this tank but I just really have 0 room for a set up right now. https://www.bulkreefsupply.com/32-gallon-rimless-aio-nano-aquarium-pro-series-fiji-cube.html
I want to cap the gravel with sand to give the corys sifting ability, but am afraid my substrate height would be too high. I'll snag some glue and spiderwood. The two nerite snails don't do much. Should've waited for the task to establish before getting them. Mystery snails are much more active on the walls and ground.
Just wait till they start laying eggs everywhere and you’ve got way more snails then you bought. Busy little boogers.
done minus a bit more planting. corys are social and zoom around. fun to watch. tetras and otos observe and partake in zooming with the corys in the evenings. gouramis stick to their own sides mostly. they started out social with each other, but haven't done as much post mating. keeping an eye on the male and have no plans to foster their children if it happens. shrimp do shrimp things. mystery snails have gotten large, graze along throughout the day. same for the otos. some of the plants are from FB marketplace, others from two LFS. had a small BBA issue on the large wendtii (FB buy) that's gotten better. CO2 down the road Spoiler: full stock is: 6 panda corys 10 blue eye gold neon tetras 2 otos (one passed the day after acclimation) 2 honey gouramis who've mated numerous times 5 amano shrimp 3 cherry shrimp, one has eggs 2 mystery snails had 2 nerites, one passed causing ammonia spike, returned other one due to aforementioned Spoiler: pictures View attachment 261372