Help Sick puffer

[vio]

hey everyone i have a puffer, canthigaster compressa to be exact. he is about 2 inches long and housed in my 15 gallon aquarium with 2 velvet neon damsels a peppermint shrimp and 25lbs of live rock. lately i have noticed he is not acting normal. usually he is always in the front of the aquarium begging to eat. lately he has been hiding a lot especially when i come in the room. he also isnt eating as much or as readily as he has before and even when he does eat a lot, shortly after, say 12 hours, he looks very skinny again. he also isnt feeding as many times a day as he used too and is acting very lethargic. even before this new eating habit he would get skinny shortly after though. my levels in my tank are as follows:
ammonia: 0
nitrite: 0
nitrate:40ppm high i know but i have a small water volume so its rought o keep down.
phosphates: 0


does my fish have worms? internal parasites? how do i go about treating him. should i dose with piperazine and how? i am very worried i am going to lose him. any help is appreciated thanks.

[leebca]

WELCOME TO REEFLAND!

First the good news: Puffers often go through a period of just not behaving normal. They go on hunger strikes and change behavior up to a few weeks. If fed properly initially, the Puffer can go a few weeks without food.

Now for the bad news: That is the wrong sized aquarium for that fish. Way too small. I would suggest returning the fish to the store or give it away to a proper home.

[vio]

thanks for your help. considering i have had the fish for close to three months i cant return him but i am working on transferring him to my dads 37gal. do you think this would be large enough? and also how can i be sure he is not infected with parasites or something that could harm my fathers set up? i find it very peculiar how he eats yet is skinny again shortly after. is this simply stress related from the environment i have him in? would the stress of treating him for something he may or may not have be worth it? i just dont want to see this creature die. any help is greatly appreciated. also i have done daily 40% water changes over the past 2 days in an attempt to relieve this animals stress. he appears better today after yesterdays change and i have just done another. Can this lack of weight gain be attributed to high no3- content? also (as if this post doesnt contain enough questions) one of the damsels i have him in with is about the same size as him and i often see him bullying the puffer (swatting with tail and body) and the puffer never seems to stress out over this but can this be causing the puffer so much stress that he is not acting normal?

[leebca]

Fish stress is a favorite subject of mine. Unfortunately, all the things you pointed out are stress sources and can and do affect marine fish behavior. As a hobbyist we try to remove as many as we can and reduce the rest. So if you see stressors, remove them or reduce them.

You have to add to your list of possible stressors, poison. Small space makes for higher concentrations of wastes and build up of proteins, etc. Also it may depend upon where the fish was collected. This fish is still collected in some areas by the use of cyanide.

This fish gets as large as 5 inches in the home aquarium. The fish should be in an aquarium no less than 50 gallons if alone or a larger tank if you want to keep it with other fish (that are not aggressive to it).

The fish remains pretty thin throughout its life. Thin is normal for this fish. However if you're concerned about its weight, review what you are feeding it and what it should be eating. Read through this post to get some food ideas: Feeding Marine Fish and Fish Nutrition

Quarantine all fish before putting them into a display tank. Instructions for this are here: A Fish Quarantine Process. If there is a problem, it will show itself during the next 6 weeks of quarantine.

There is no big harm in performing certain treatments even if the fish is healthy. For instance, de-worming an eating fish is recommended even if the fish has no internal parasites:Strange Excrement from Fish -or- How to be a Super Pooper Snooper

However, treating for some diseases just for the sake of it is not a good idea. When treating for something unknown, you are perhaps missing symptoms or signs of what the fish really has and thus, treat for the wrong thing, not really curing the fish of its problem.

[vio]

good news my puffer is acting much much better after a few large water changes. he is back to begging for food and eating out of my hand again. i think the excess nitrates were really bothering him. i also am getting a much larger home for him, 55+, in the next week or so so this little guy should be very happy really soon. thanks for your help lee.