My Puffer Fish gree are lathargic and have a white film on them

Question
When I first got my Green Spotted Puffer Fish, They were very active. They had extremely bright colors and were very playful. Now they just float along and they look kind of sickly. I don't know if I'm not feeding them properly or they just don't like the environment. I feed them frozen shrimp and a some small snails. They are in a twenty gallon tank with a few other tetras. Please give me your input on what I can do better for them. Thanks, Jon

Answer
Good morning Jon, thank you for your question.

I encourage you to research the care requirements for your GSP. I am sorry if the pet store did not prepare you for this, unfortunately many petstores themselves tend to keep GSPs inappropriately. Your GSP will not be compatible with the tetras for two reasons...two very substantial reasons!

1. The GSP is actually a brackish water fish. Keeping a fish that belongs in brackish water in fresh water is detrimental to their health. If you want to keep your puffer (puffers?) happy, you will need to put them in a separate tank - or put the tetras in a separate tank - and begin slowly acclimating them to brackish water. You'll need marine salt and a hydrometer (to measure salinity) for starters...

2. The GSP is a predatory fish by nature. It needs a more varied diet than what you are providing. As you know, it will not eat flakes...it would much rather eat your tetras! It is their nature to go after live foods. You can offer many other kinds of shellfish and seafoods besides shrimp.

I will link you to a site that discusses feeding in detail. Live foods such as ghost shrimp should be offered, gut-loading them with nutritious foods such as pellets and wafers. Invertebrates such as crayfish, crabs, and snails the size of their eye can also be offered live when your puffer is big enough to eat them. Live foods such as goldfish or minnows are necessary and undesirable due to their rearing conditons and low nutritonal value.

There is really so much you need to know, Jon, I cannot even begin to convey it all to you in this message. Instead, let me link you to a site with a resident puffer expert (her handle is Pufferpunk) where you can read all about your GSPs and how to care for them. You can even read about how to acclimate from freshwater to brackish water. Here you go:
http://www.wetwebmedia.com/BrackishSubWebIndex/gspsart.htm

Do read the linked files above, as much as you can. Your puffer(s) can live over a decade with the right care. Do realize they are specialized fish with fussy diets and needs...perhaps you weren't ready for that kind of commitment in your community tank. If you decide to return the GSPs to the pet store, please tell them that you are unhappy with the misinformation you received and unhappy with the way their GSPs are being housed. There are truly freshwater puffers out there, such as dwarf puffers. This is NOT one of them!

Take care, and good luck with your GSPs.
Nicole