goldfish population

[Goldiesmother]

I have been lucky enough to successfully breed about 100 baby goldfish. Does anyone know how many I am safe to keep in a small pond 3 foot by 3 foot ? Also when can I give them to friends, some want to keep them in tanks.

 

[dieselplower]

Minimum 20 gallons per full grown fish. I prefer 50 gallons per fish in my pond. How deep is the pond? multiply length, times width, times, depth, times 7.5 to get gallons. you can give them to your friends whenever you want, just make sure they dont do dumb things like put them in bowls or small tanks with no filters.

 

[Waterbug]

Size of the pond doesn't really affect weather or not fish survive or not. They could all die with 100 gal per fish or all live with 1/2 gal per fish. Keeping water parameters good is what keeps fish alive. The more water volume per fish the more diluted problems are, so the longer you have until fish die. But we could be talking a few extra days by doubling water volume per fish. But if something like ammonia is increasing and it's allowed to increase then water volume isn't really going to matter. Might buy you some time, but it still needs to be fixed no matter the pond size.

Now there is a point where the size of the pond, by because of the liner surface area, kind be a big enough bio filter to handle fish wastes and the pond can handle a certain fish load. But absolutely no way to determine what that ratio of size to fish is ahead of time. Many other factors other than size. Some rules of thumb is as close a guess as you can get and those are all over the place.

 

[JohnHuff]

I didn't get anything out of this. Did anyone else?

Size of the pond doesn't really affect weather or not fish survive or not. They could all die with 100 gal per fish or all live with 1/2 gal per fish. Keeping water parameters good is what keeps fish alive. The more water volume per fish the more diluted problems are, so the longer you have until fish die. But we could be talking a few extra days by doubling water volume per fish. But if something like ammonia is increasing and it's allowed to increase then water volume isn't really going to matter. Might buy you some time, but it still needs to be fixed no matter the pond size.

Now there is a point where the size of the pond, by because of the liner surface area, kind be a big enough bio filter to handle fish wastes and the pond can handle a certain fish load. But absolutely no way to determine what that ratio of size to fish is ahead of time. Many other factors other than size. Some rules of thumb is as close a guess as you can get and those are all over the place.

 

[JohnHuff]

To answer your question, I've seen many guides, this one is as good as any:
http://www.aquameds.com/articles/article?article_id=29

 

[Mmathis]

I didn't get anything out of this. Did anyone else?

I did. It just may be a little too much info for the OP, but good info.

 

[Waterbug]

I didn't get anything out of this. Did anyone else?

Would pictures help?

 

[JohnHuff]

Would pictures help?

Yes, please!

 

[dieselplower]

I did not learn anything from his post but it would seem helpful for a newer ponder. I think the point was if you can keep the ammonia, nitrite, and nitrate at acceptable levels through use of filtration and benificial bacteria then it doesn't matter the stocking level. A pond stocked at 50 gallons per fish could have worse conditions than one stocked at 20 gallons per fish if it is not maintained properly. i also think it is proper to give fish some room and that overcrowding should be avoided in a garden pond environment. sure he didn't say all that but the question has already been asked and answered hundreds of times

 

[Waterbug]

Water volume only affects how long it takes for fish to die if an ammonia problem exists. Obviously if no ammonia problem exists it doesn't matter what volume of water is used.

More details:
Column A has 1 Goldfish in a volume of water, say 40 gals.
Column B has 1 Goldfish in a smaller volume of water, say 10 gals.

Yellow bubbles coming out of the Goldfish is ammonia, toxic. Both Goldfish A & B produce the same amount of yellow bubbles.

After 5 days the Goldfish in both tanks have produced 14 bubbles of ammonia. The ammonia bubbles spread out in the water.

Maybe this is the tricky part and maybe where the myth comes from...as fish keepers we really shouldn't care how many bubbles of ammonia there are in the tanks. We should care how many ammonia bubbles our Goldfish breathe in, because that's the toxic part. Ammonia just floating around in the water doesn't hurt fish at all. It's the ammonia hitting the fish's gills and getting into the fish that is the problem.

Chances are higher Goldfish B will bump into an ammonia bubble and breathe it in. Goldfish A will also be bumping into ammonia and breathing some, but not as much probably.

After 5 days Goldfish B has probably breathed in 4 times as much ammonia as Goldfish A. That starts make Goldfish B feel sick. Goldfish A doesn't feel as good as on Day 1, but doing OK.

By Day 10 Goldfish B has breathed in too much ammonia over the past 10 days and dies. It's not just the concentration level, it's also the time the fish was exposed to those elevated levels.

Goldfish A has been in water with a lower concentration because of the larger tank...so on Day 10 is still alive, but now he too is starting to feel the effects, starting to get sick.

Even though the concentration of ammonia never did reach the same level as it did for Goldfish B, Goldfish A has been in the ammonia contaminated water for a longer time. He's been feeling poor for a longer period. At Day 15 Goldfish A also dies even though he didn't breathe in as much ammonia as Goldfish B.

Yes, the larger water volume did allow Goldfish A to hold on longer but the end result is the same.

The water volume myth...
The myth is that there is any ratio of water volume to fish which is safe. That doesn't stop many people to express their opinions as if it were relevant and so opinions range all over the place. 10 gal/fish, 1gal/1" of fish, 100gal/lb of food fed, on and on. Just opinion, pulled out of the air. One is as valid as the next.

A fish keeper who thinks 50 gals per fish, or 100 gals per fish is safe, or proper, or some kind of standard of safety is likely to be very disappointed by reality.

Increased volume at some point does solve the ammonia problem in ponds.
A pond is a living system, always in change. Increasing volume does increase that living system and a pond's ability to deal with ammonia.

Maybe this is where the myth comes from. A person looks at their pond and see their fish are alive, the pond is 1000 gal and there are 20 goldfish and then believes 1000/20 = 50 gals per fish, so that must be the magic number. I don't know. I suspect more likely people just read a number and repeat it.

It's certainly reasonable when designing a pond to have some starting point, some rule of thumb. You have to start some place. But often a rule of thumb is given more as a safe level, like the volume of water to fish ratio mattered more than a tiny bit.

Say in our example above that the small tank went green with algae on Day 5. That algae would eat all the ammonia Goldfish B could produce. By Day 15 Goldfish B would still be alive and happy while Goldfish A in clear water would be dead.

Or say both tanks stay clear for whatever reason. Look at the length of the black liner. Much longer in the larger tank. That allows more space for more ammonia consuming bacteria to grow. Tank A has a better chance of growing enough bacteria to consume all the ammonia produced by Goldfish A. However, we're right back to the same problem...how much space is needed for ammonia to be consumed as fast as it's produced? Unknown. These bacteria are living creatures, whether they can stay alive and reproduce to great enough numbers varies a lot. It's meaningless to say 100 sq ft of liner will support some number of fish.

Increasing the water volume does generally make keeping fish easier. It buys you time and can even solve the ammonia problem completely. However, this can only be known by monitoring ammonia levels...not by some formula of water volume to fish ratio.

 

[dieselplower]

Good one Waterbug. I like your pictures hahaha.
Generally, when i make a recommendation about gallons per fish I assume that a person would know that a higher stocking level would mean more work. More water changes, more water testing, more cleaning out the filters, etc. I see how this is a problem. Having answered the same question 100 times I start to feel like the above is obvious but to someone asking the question, it probably isn't. 20 gallons per fish will be a high maintenance level. I have chosen 50 gallons per fish for my pond because it is a good balance of a large number of fish with a relatively low amount of maintenance. 100 gallons per fish would be even easier. Of course all of this is still relative as ponds will have different amounts of Sun, rain, filtration, food thrown into them, temperature ranges, etc. And of course I'm only talking goldfish here... It really is all relative.

 

[callingcolleen1]

I have seen large goldfish kept very well in a small glass bowl, lady would let water sit overnight in pail and change the fish bowl water every day! She had two beautiful big fish in a bowl I would would consider way too small.

I have seen large ponds with only a few fish and owner had lots of trouble with fish dying.

I have seen a small pond with no pump, ton of leaves at bottom of little 50 gallon pond that was right under a large tree, and this pond had several big beautiful comet goldfish, all in very good shape and color. I rescued those fish many years ago....

 

[Waterbug]

dieselplower, I wasn't trying to bust your chops, I totally get people post questions in forums to get 10 or less word answers. The beauty about Water Gardens is none of it really matters. They're pretty forgiving and worst case losing $2 worth of feeder fish isn't a big deal.

 

[JohnHuff]

WB delivers! I missed those pics until today.

To be honest, I really like your posts but sometimes I think they're too technical, deep or long and need to be tailored to the recipient. Sarcasm aside, did you think that that was what a first time poster expected to hear?

dieselplower, I wasn't trying to bust your chops, I totally get people post questions in forums to get 10 or less word answers. The beauty about Water Gardens is none of it really matters. They're pretty forgiving and worst case losing $2 worth of feeder fish isn't a big deal.

 

[dieselplower]

dieselplower, I wasn't trying to bust your chops, I totally get people post questions in forums to get 10 or less word answers. The beauty about Water Gardens is none of it really matters. They're pretty forgiving and worst case losing $2 worth of feeder fish isn't a big deal.

It's cool man, I know you weren't. When I first started fish keeping I also thought it wasn't a big deal if some of the fish I dumped into my freshly filled pond (well water) died. I bought 20 feeder fish, threw them into a 150 gallon preformed with inadequate filtration, and had 9 dead ones within a week. Now I take pride in not losing any fish. I value them more than the 13 cents I can buy them for. Anyway, I enjoy posting on here, helping other people, and debating with some of the more experienced ponders who can and do teach me things even though I wont admit it. Cheers.