Loaches Online Forum

Hi all,

I am new to the forums and have had a thought about my little "runt" in my loach aquarium. I currently have 5 loaches (4 clown loaches and a yoyo loach) in a 30g aquarium. I do water changes weekly, has a HOB biowheel filter, and a bubbler. Tons of hiding spots. AND yes, I realize it's a small tank and will soon be converted to grow out tank for other fish while I am getting my 55g cycled as I write.

My oldest clown loach, who is going on a year, is about 5-6 inches. I purchased 2 new ones about 5 months ago then another about 1 month ago. It seems that the smallest one, aka the runt, does not seem to be growing...at all. I notice grow in the three of them except the little guy. This worries me.

I feed them a consistent rotating diet of algae thins, brine shrimp and blanched zucchini/cucumber. The runt eats great and from what I have read, sometimes the alpha loach doesn't let the little guys eat but this is NOT the case in my aquarium. Everyone eats happily. Just the little guy hasn't grown and it worries me because I have read that most clown loaches grow a lot in their first year, which I have experienced with my other ones.

I could only guess it's a parasite(?) but not really sure. I have included pictures in this post and would like to hear as much feedback. Thank you!

Above right


he's the one on the top, depth is a little weird on this one.

to the left

Where do you live (country)? I have noticed that runty clowns, often have a short nose, and I am pretty sure they are being captive bred. This guy looks like one of those. Also did you treat for internal parasites? When I have stunted fish, the first thing I do is check for parasites.

I would also do 25% water changes, maybe 30% to reduce stunting, especially since your tank is a bit small, even for small clowns. Also I am in Florida and know quite a few fish farmers, including ones that breed clowns, and they have told me that if their clowns are in hard water it stunts their growth. Florida's natural water is like liquid rock, so if they want their clown fry to grow, they need to use RO and rainwater.

I live in the US as well. I do water changes once a week >25%, cleaning the gravel very clean. I live in DC and put stress coat water conditioner in the water to remove chlorine and such but maybe my water is too hard for growth?

Also, I have recently considered parasites could be a problem. He eats fine just like the others just no growth.


I am more then willing to try some parasite removal treatment however I am in the dark about what to use. I have read some posts about Jungle Parasite Clear. Would you suggest that or is there a better treatment?

Thanks, much appreciated!

I'd suggest NOT applying any type of medication as you don't know what the issue is, or even if there is an issue. The only thing you have to go on is growth rate in a 6 month period.

Craig_ wrote:I'd suggest NOT applying any type of medication as you don't know what the issue is, or even if there is an issue. The only thing you have to go on is growth rate in a 6 month period.

If the loach has stunted growth, will he ever grow more? Or is stunted growth permanent?

If you catch the reason early, and treat, the fish can start growing again. For example: Many bottom feeding fish have added opportunities to pick up internal parasites, so I routinely quarantine and treat Loaches, Cats and other bottom fish for parasites. Before they are showing symptoms is the best time to kill the parasites.

Diana wrote:If you catch the reason early, and treat, the fish can start growing again. For example: Many bottom feeding fish have added opportunities to pick up internal parasites, so I routinely quarantine and treat Loaches, Cats and other bottom fish for parasites. Before they are showing symptoms is the best time to kill the parasites.

How can you tell a loach has parasites?

Are there safe treatments to treat the whole tank with since the loach has been there for 6+ months?

Thank you!!!

Often a loach with parasites looks thin even when it eats well, and they don't grow.

I treat my loaches with levamisole. Doesn't hurt the fish and does a good job at wiping out certain internal parasites. If that doesn't do the trick, then I go with praziquantel. Read the instructions carefully, and watch the fish. If they react adversely, do a water change.

If parasites are suspected and the fish has been in the tank for 6 months then all the fish have been exposed, so yes, treat the whole tank.