Ick and spotted green puffer question!

[graceful.04]

So the other day I saw a $19.00 spotted green puffer with lots of ick on him but fell in love anyways. I asked if I could get a discount to take the puffer home and get him healthy again. I ended up getting an offer to take him for free, so of course I jumped on it, complete impulse buy. He is now being treated in a five gallon tank with ick meds but the issue is that I've never dealt with brackish fish before. I do have the appropriate salt for him and I was planning on adding it over time, but I don't know how much. Can anyone suggest a good dose for a five gallon tank that would be ok for my puffer or can he do well in just fresh water? Also any other advice would be greatly appreciated! Thanks!

[Obsidian]

He needs a bigger tank #1 but being treated in the 5 ga is fine. A green spotted puffer should be in at least a 15 ga. Some would argue they need much bigger.

For brackish the best thing you can do is get a salinity meter for the tank. That will measure how saline the tank is so you can keep it in a healthy range. As for that range I will leave that part up to someone who knows, because I forgot LOL.

[TheOldSalt]

1.010 -1.012 is good for brackish fish.

[kay-bee]

Being scaleless, you may want to exercise caution when treating green spotted puffers (GSPs) for ich with meds, especially those that are copper-based.

A refractometer (preferable) or hydrometer is required to monitor the salinity of the brackish water.

Gradually transitioning the aquarium (assuming the GSP is the sole occupant) to a brackish or even saltwater environment (increasing the specific gravity by .002 per week) to allow for FW to SW beneficial bacteria change over to occur. In a 15gal tank this can be attained by adding approximately 1 tablespoon (3 teaspoons) of completely mixed and dissolved marine salt into the tank on a daily basis.

Going up to saltwater salinity (1.020-1.025 SG), or even high-end brackish (1.015 SG) will kill and prevent the reappearance of FW ich (most GSP's in LFS's are kept in FW containing some salt rather than true brackish parameters).

GSP's get upwards of 5" or 6" and will require a larger tank in the future (due to size and bioload), ~30gal.

[graceful.04]

Thank you!! You're all so helpful! I hope my puffer makes it, he's just the cutest and friendliest thing!