I saw your post in the pipe thread and you kind of need to consider this:
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Zots are pretty lazy little SH and spend most of their time hitched waiting for food to swim by.
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Speaking of food, zots require daily feedings of live food (BBS and/or copepods). They don't ever really train to frozen like larger SH.
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Since these fish require small live food, you'll likely need to culture BBS and/or copepods to keep them fed.
With all the live food in the tank, you'll likely get hydroid blooms, and 'droid stings can kill zots (many folks use a "sterile" setup to mitigate this).
If you get a M-F pair, they will likely breed and crowd-out your 3 gal, so get a same sex pair.
The lifespan of a zot in captivity is about 1.5 to 2 years tops, so, for a special needs fish, you may not want to go there.
So, yes, zots are cute, and relatively cheap to buy, but the cost of ownership in both time and food may not be what your looking for. Oh, and vacations? Since SH lack a true stomach, they must be fed at least once daily, so you'll need to have a "trained" fish sitter come in (they'll have to know how to hatch BBS unless you supply them with bottles of live pods).
I'm not trying to put you off zots, but I do want you to know what you're getting into up front...personally, we don't keep them because it's basically like having a perpetual SH fry tank, and we've "been there, done that, and have several T-shirts".