Stunting... Water/Space/or both?

[twoodrough]

What really causes stunting?

You can have bad water quality in a big tank, or great water in a smaller than recommended tank. I would take good water and less space over more space and bad water for my fish.

Right now I have a young fantail in a 20, great water quality, and will move him to a larger tank in a couple years when he is bigger. Am I really doing that much harm by having him in a 20 while he is young and small (about 2inches), as long as I stay on top of the ammonia and nitrates?

 

[Hholly]

I've always wondered about this too as I've seen several giant fish in tiny tanks over the years. (Like a pacu in a 20gal. at a pet store when I was growing up. It was there for years.)

 

[Wy Renegade]

In truth, its a way more complicated issue then simply one or the other. You have too consider growth rate, overall size to which the fish should grow, overall bioload of the tank, etc. Generally with more fish (overstocking) in a smaller tank, you can get away with it for a time by overfiltering. Overfiltering however isn't going to compensate for a lack of growing room. If actual space is the issue, then overfiltering isn't going to solve the issue. If the fish in question does the majority of its growing within the first few years of its life, then keeping it in too small of a tank for that period of time is going to be an issue, regardless of water quality. If you were talking a couple months, that would be a different issue. We used to believe that fish grew to the size of the tank they were kept in, and then stopped growing. We now know that while they stop growing on the outside (i.e. stunt), they don't stop growing on the inside, and the result can significantly alter their quality of life and shorten their life span. Not that it is a great analogy, but somewhat similar to the children that grow up being kept in a closet. Nobody can say that a closet is going to stunt a childs growth because they will out grow it, but in truth there isn't enough space or socialization opportunities in the closet, and that child is affected for life. Unfortunately, same story on the goldfish. It may not appear that the fish is growing too much for the tank, but the growth opportunites simply aren't there, and the fish will be affected.

 

[jlk]

Yes, water quality is a big issue with stunting and a fish's health and well being as well. Unhealthy water equates to unhealthy fish that wont grow properly or live full lives. Less water volume means a tank will become toxic quicker and the concentrations of toxins will be higher rather than being diluted in a larger volume of water.

The second issue though is a hormonally based one. Its been scientifically documented that fish release hormones that will affect their growth and inhibit it further. Once again, this factor is influenced by water volume- the less the water volume, the more concentrated these hormone levels will be. Serious fancy breeders follow hefty water change schedules (as in 50-100% daily) for both of these reasons to ensure optimal growth.

Goldies do most of their growth in their first 2-3yrs of life until hitting sexual maturity, upwards of 1/2in to an 1in a month (depending on breed). They continue growing after hitting sexual maturity but at a much slower rate. The link below provides a growth chart- is not 100% accurate and gives growth rates on the small side of things but it provides an excellent visual of goldfish growth vs time. Hope this addresses your question!

http://www.fishkeeping.co.uk/pdf/goldfish size chart.pdf

 

[twoodrough]

So it kinda answers my question, almost. He is in a 20 now. I thought 20s were okay for fantails. But if he gets to be 8 inches (I thought they only got to be 5-6 inches) that won't work in the long run. I knew going in I was going to have to move him someday, and I was going to try to upgrade when he was about 4-5 inches. I just got this 20 and am not "allowed" to get another tank for a couple of years. I thought I would be okay for that long.

 

[Hholly]

So it kinda answers my question, almost. He is in a 20 now. I thought 20s were okay for fantails. But if he gets to be 8 inches (I thought they only got to be 5-6 inches) that won't work in the long run. I knew going in I was going to have to move him someday, and I was going to try to upgrade when he was about 4-5 inches. I just got this 20 and am not "allowed" to get another tank for a couple of years. I thought I would be okay for that long.

Just a thought... Keep looking at Craigslist. Sometimes they give tanks away for free or close to it.

 

[twoodrough]

That's where I got this one. I am on CL lock down for a couple of years.

 

[clearancepuppy]

That's where I got this one. I am on CL lock down for a couple of years.

That is hilarious! (Me too ... Hubs orders lol)

 

[twoodrough]

So - I get the hormone aspect of stunting now. But, wouldn't those hormones be removed during water changes each week and keep them to a lower level that was not detrimental? At least while the fantail was only 2-4 inches long? If I were to do 50% water changes every day on a 20G with a fantail goldy, woudn't the hormones be taken out? I don't think I would do 50% wc every day, but shouldn't there be a point where enough water changes would nullify the hormones? If I keep up on water changes so that my nitrates are at or below 10, shouldn't that keep the fish from being stunted?

Thank you for your patience! (And being nice after my vent on the other thread!)

 

[jlk]

You are correct- the answer is water changes. Obviously, no one expects you do to daily 50% wcs (I dont even do this!) in a cycled tank but big, more frequent water changes will help to keep everything in check.