The Puffer Forum

I purchased a GSP about 4-5 months ago as a baby (about an inch long). Since then, he seems to be growing very slowly (inch and a half). GSP is in a 29 gallon tank (from beginning), fed once a day and shares tank with 8 mollies. Can his growth have been stunted? Does the growth cycle take time?????

I believe their growth rate is relatively slow at that age/size - after 2-3" they're growth rate picks up more. Does your GSP ever seem bothered by the mollies or anything?

Well, they do grow slowly but IMO that tank is way overstocked. I can't imagine 8 mollies in a 29, much less a puffer in addition to that. Overstocking a tank will contribute to stunting a fish.

What kind of water changes are you doing to keep levels under control?

What are the water conditions and parameters?

Watar change schedule?

What is being fed?

The GSP is very happy with the mollies. No nipping or any fighting (at least for now). Started with 6 mollies to cycle tank. Mollies have babies all the time. Eat their own. Only two have survived.

Water change a quarter tank once weekly. About 1/3 to 1/2 once a month. Test water weekly. Not certain of current parameters, but well within acceptable parameters.

Feed GSP assortment of bloodworms, shrimp and mussels. Mostly bloodworms though.

So you think it just takes time for him to grow? How long do they stay that size (couple years)???

baggo wrote:Not certain of current parameters, but well within acceptable parameters.

If you don't know what they are, how do you know they are within acceptable parameters?

salinity is at 1.0. I don't have the numbers with me. the test showed everything within the parameters. Nitrates do rise at times and I stabilize it by water changes.

1.0 salinity is no salinity--freshwater. With nitrites & ammonia, there are no "acceptable" parameters--must be 0 at all times.

Just as a comparison, I got my GSP at under an inch (it was the same size as my juvenile DPs when I got it) in February I believe. It is now 2.5-3 inches long. It lives in a 29g tank which at one time held a half dozen mollies but they have since moved out. We've been slowly raising the salinity using marine salt for the past 2 months. He's fed once a day at most, sometimes skipping a day between feedings. His diet is blackworms, shell-on shrimp and ramshorn snails (snails at least once a week, usually more like twice a week).

With as heavy a bioload as you have in your tank, I would definitely recommend larger volume water changes of at least 50% weekly. I'd also recommend lightening the bioload by either rehoming some if not all of the mollies, or getting him a bigger tank. IME, the GSP never bothered the mollies, it was the other way around. The mollies were bullying the GSP and preventing him from eating sometimes, particularly when it was a piece of shrimp clipped to the tank. Once most of them were removed (there are 4 small juveniles in his tank at present), he was able to eat better and isn't nearly as skittish as he was.

What kind of filter are you using?

use biowheel filter. u think i should remove some of the mollies?

Yes, all of them if at all possible. Is the biowheel rated high enough? Overfiltration is vital for puffers so using a higher rated filter than normal is important.

Do you do regular maintenance to the filter - cleaning the media and whatnot?

Are you adding salt at all? Doesn't sound like it. GSPs need marine salt. There's an excellent article in the library here on the correct care of GSPs. I highly recommend reading it if you haven't already and if you have, you should probably read it again. I read it at least once a month.

I would definately remove all the mollies, the tank is barely big enough for the puffer by himself as it is, technically its not big enough for him if you want full growth (29's really only hold about 25 gallons and 30+ is recommended for a single GSP with no tankmates).

You will need the marine salt too, they are not freshwater fish and aquarium salt does not make brackish/marine water, no matter what the store tells you.

Most of us do 50% water changes on our understocked tanks, just because puffers are such dirty fish (messy eaters), and clean water is always a good thing. You are currently doing small changes on a, in my opinion, very overstocked tank.

So yes, there are quite a few things you can change to help him grow faster. Get the mollies out of there, start adding a little marine salt with every water change (don't raise it more than .002 each week), and start doing larger water changes. A larger tank for him would really be the best plan.. But for now the above will help tremendously. The sooner the better too, he sounds like he's already being stunted and you want to stop the process ASAP.

yes, we use marine salt and add it with every change to bring it back up to
1.010- 1.012 (which is current salinity level) we use a hydrometer to measure.
the biowheel is for 50 gal. so we're good there.
we change filer media every 2-3 weeks.
my girlfriend is obsessive, she covers all bases. just cant figure out why jet
isnt growing!

All this info is very helpful.

Well IMO you shouldn't be changing the filter media. It doesn't need to be changed unless its falling apart. All it needs is a good rinse and squeeze in the tank water that you've removed during water changes.

Hydrometers become pretty unreliable from my understanding after just a few uses. I'd recommend investing in a refractometer, which can be found on Ebay pretty cheap.

Very true. By changing the filter media you are taking out good bacteria. And there's no need for carbon at this point either. Just rinse it out to get the "gunk" out and put it back in.

Everything else still stands, bigger water changes, bigger tank, etc.