29 BW startup

I am by no means a brackish expert, but these are my immediate thoughts. Anyone is welcome to repute them.

Figure 8's require 30 gal each at full grown size. Also, I believe they are fully marine at adulthood, so you'll have to increase salinity gradually.
Also, puffers generally do not do well with other species because they love to nip fins. So most people keep puffers in species-only tanks. But if they're with gobies (bottom dwellers) who have plenty of rocks and caves to hide in, maybe they'll be OK. I'm guessing you won't be seeing the gobies much, though.

Anyone else have any thoughts?

I think plah831 has the figure 8 and green spot puffers mixed up. Green spots do grow about 6 inches and are full marine when mature.

For a figure 8 in a 29g, light brackish is required at around 1.005. I would not put another f8 in there but knight gobies are an option. My 29g has a f8 and two knight gobies. The thing about those gobies is they can be hyper active sometimes which gets bothersome to the puffer. What I done was set up a lot of rockwork and got a male/female pair of gobies so they could keep themselves occupied.

Make sure you have a supply of crunchies for the puffer. Pond snails are perfect but mine will also eat bloodworms, krill, mysis and crickets. Knight gobies will eat practically anything. During feeding you will see why they sometimes get called dancing gobies.

You can sex the gobies by their appearance. The male is more slender with larger fins.

you're right, I think I did get species mixed up. Are f8's less aggressive than most puffers?

Well like all puffers they can be agressive. I find knight gobies are able to handle themselves quite well. They are so fast and actually prefer the cover of rockwork so they only bump into each other when there's food in the tank. The gobies have learned that they can't quite get through a snail shell like the puffer, so they don't waste their time on it.

reiverix said:

I find knight gobies are able to handle themselves quite well. They are so fast and actually prefer the cover of rockwork so they only bump into each other when there's food in the tank. The gobies have learned that they can't quite get through a snail shell like the puffer, so they don't waste their time on it.

Click to expand...

Interesting! I can see how this would help simulate nature (where all kinds of fish might come into contact) and keep the gobies on their toes

I've saw the gobies in what I think was a mating ritual but I cannot be 100% sure. They lay their eggs on the roofs of caves (guarded by both parents) which makes it almost impossible to tell if they have bred, in my tank anyway. The fry are notoriously difficult to raise so I haven't even bothered trying.