For a 30g Tank, I'd say F8 or GSP or a handful of DPs even. I have 10 DPs in my 30g. Just make sure to keep only 1-2 males and the rest female. F8 will start fresh , but will need brakish. GSP will start out fresh, but then need brakish and eventually salt. Brakish isn't hard at all. I would suggest adding crushed coral if you go this route. It will help regulate your PH. Both the F8 & GSP will want water in the 8.0-8.2 range. DPs like it closer to 7.0. I think 7.2-7.4 is where they seem the happiest. F8s will be happiest in water with a SL of about 1.015. GSP will be happier in about 1.025. DPs are fresh their entire lives. Just be sure that you slowly raise the salt level (SL) or the poor lil puff will go into shock. You should raise the SL about .002 per week until you reach desired level. Your LFS will most likely have them in fresh or very low brakish. So, it is best to add them to your cycled tank, then slowly raise the salt level. The F8 only needs 1.005 until they reach about 2 inches, then I would just shoot for 1.015. The GSP will want 1.10 under 2", but will slowly want more salt. You don't have to go full on salt with a GSP, although many will say it's better for them. If you decide to keep a GSP in brakish long-term, please make sure it is at least 1.015-1.020. I personally keep my DPs 1.001-1.002 water. But, I do this only to encourage breeding. They seem to breed more after the water goes fresh again. If you don't want babies, keep it fresh. Never keep it at 1.002 for a long period of time though, only a couple months at a time, when you see some courtship. But, it will all be a slow process with their salt needs. GSPs can be very hard to breed in captivity. In fact, most puffers are very shy when it comes to romance. DPs ... not as much. All 3 of the puffs I mentioned love snails. But, they mostly eat ramshorns. The GSP will have no problem with the trumpets when he is bigger. The F8 will eventually be able to eat trumpets also. The DPs will never eat trumpets, most likely. The reason being that the ramshorn snails have a thin shell, but the trumpets have a very hard shell. the babies could never bite through. The reason I mention these three specicific breeds of puffer is because they tend to be the easiest to find locally (Florida). If you live close, I could send you a starter set for free if you want. I wouldn't really want to ship them cross-country. 2-3 days shipping is best. It's easy to find them on eBay all over the US. Don't worry about the different colors. I started with some blue, albino, leopard, etc etc... After a month, they are all pretty much red, the colorfuls ones died off and their babies never turned color. They all start out red though. I started with about 20 ramshorns and had about 1000 in 3 months. It's best to keep the snails in their own tank. Puffers don't always let them live long enough to breed.
My personal vote would be to get 8 DPs (pea puffers, dwarf puffers). They stay freshwater their entire lives. They are really easy to take care of, low maintenance. But, it is very very important they have ramshorns snails, because it will be about 90% of their diet. I have managed to get a few of mine to eat freeze dried mysis shrimp, but it isn't a staple food. The best ratio is 1 male and the rest female. I tried that, but one of my lil girls might be becoming a boy. Or, perhaps she is just a lil scrapper and loves to bully.
If you want 1-2 puffers, I would say 1 GSP or 2 F8s (1 male, 1 female or 2 females)
All of them are very very cute and they all have unique personalities. I like the idea of having 10 1 inch puffers with their own quarks. But, a lone GSP will be a great pet. He will act like a dog when he sees you and come running to the glass. Some puffers will always do that even if kept in a group though. 7 of my 10 DPs come running when they see me.
it really can be a hard choice. but, whatever you do, please do your research on that particular puffer. Babies are cute, but most puffers will want a LOT of space when they get bigger. If you do go with a 55g, you could get 2 GSp, but that would be pushing it. 3-4 F8s in a 55 would be fine, max being 6 IMO. With DPs, you could probably have about 30-40 of the lil buggers in a 55g.
With any group of puffers (anything over 1), you will need a well planted tank for them to claim territories. otherwise, you will soon have a dead puff. The other thing to consider is that all puffers are very messy eaters. If you get a 30g tank, I'd go with a 55g+ filter. with a 55g tank, at least a 75g filkter or even a small canister. with the DPs, they may be small, but they make a mess nonetheless. Expect to have to do 50% water changes every week with any puffer. I have managed to get away with 50% every 2 weeks, But I'm using a 75g filter in my 30g tank. If you want your puff tank to be anywhere close to a normal maintenance tank, it's not too hard. You just have to plan ahead and get proper filtration and hiding spots.
The next problem you will have are tankmates. For the most part, it's best to have a species tank for any puff. I do keep some black neons with my DPs and they leave them alone completely. Probably because the black neon looks alot like an oto ... not too tasty. There really arean't any brakish algae eaters also. plecos and otos CAn live in brakish, but they will have a miserable life and that just isn't nice. with DPs, otos seem to do best. But, a nice small pleco will work also. I personally love bristlenose plecos ... they have a cute mustache and are algae eating machines and they rarely grow much past 3". The clown pleco is another good choice, but you will never see a clown pleco and as it gets older will need wood to eat. technically all plecos are wood eaters though. But, the clown pleco won't eat nearly as much algae. Again, they also have their own personalities. I had a clown pleco that was out all day cleaning the glass. but most hide all day and come out at night. bristlenose are active throughout the day and are constantly cleaning. otos are great that way also and they stay very small ... about 2".
You really can't go wrong with any puffer. They all make great pets. It's alot like have a dog in a fish tank. Some are pit-bulls and some are poodles. Almost all of them will love their owner and recognize them. You just need to be prepapred for your puff's needs. With most puffers, less is better. The DPs are the only ones I have found that actually do very well in large groups. They will still argue, it's in their nature. The PufferPedia has been a great source of info for me. But, it's good to read what others say in the forums. You might learn a lot more from the forums.
LOL, I think I just hi-jacked this post, sorry. If you want any more help or advice, feel free to PM me.
Or else, I might just write another book in your post
If you want a saltwater puffer, the GSP or Valentini are both good choices for a 30g. But, there are so many species and they are all great.
FW, BW or SW ... That is the question. Plan Ahead Plan Ahead Plan Ahead
With Proper Care most Puffers live 10+ years.
Good Luck,
Bob
