Fish Number Comparison Question

[mant01]

Im new to the forum so please make an allowance if this is common knowledge here. I was wondering why fish numbers are so low in ponds in comparison to what you see in aquariums? Ive seen people say 50 gallons per goldfish yet in a tank there will be quite a few. Thanks

 

[Mmathis]

Not sure I follow what you are saying. Assuming you are only talking about goldfish...... The ratios for pond vs. tank should be about the same. A lot has to do with filtration. Goldfish (and koi) produce a lot of waste. Plus they can grow quite large and easily and quickly overcome a biosystem.

Now, if you’re talking about goldfish vs. tropical fish......consider the size of the fish. Goldfish are larger than the majority of tropicals.

If there is something else you are asking......I’m sorry but you’ll have to be more specific (I’m not the brightest fish in the pond).

Oh, and welcome to GPF!

 

[mant01]

Sorry for not being clear. I meant in cold water aquariums you often see a large number of fish being kept in a relatively small environment but in ponds the suggested numbers per gallon seems low in comparison. For example I have a 300 gallon pond and was told that it could hold about 6 goldfish but if that were an aquarium with 300 gallons you'd see many more than that. Just wondered why the difference.

 

[Mmathis]

I just looked up an online fish load calculator. It said for a 300 gallon pond you could have 15 fish inches. Not 15 fish, but 15 total inches, for all goldfish. We do suspect that these calculators aren’t 100% reliable, because a lot depends on your filtration system. Beyond that, I really can’t answer your question.

Well, maybe this..... If 20 gallons Is what’s recommended minimum size for a goldfish kept in an aquarium.....then add 20 gallons for each goldfish....15 x 20 = 300.

 

[mant01]

Ah right thank you.

 

[Jhn]

Agree with Mmathis, filtration is a factor, type of goldfish, as well. Also, in a pond goldfish will reproduce and your goldfish population will grow.

Never liked rule of thumb for fishkeeping in general. Better off, knowing and understanding your particular fish species needs. The idea when keeping pets is to keep them for their natural life span. Common sense tells me keeping a bunch of fish that get a foot long in a 50 gallon tank will not end well, w/o me majorly upgrading my tank size and filtration, eventually.

 

[mant01]

Thank you for the replies. I bought a Hozelock 3003 easyclear 3000 for my pond but havent even added water yet never mind fish lol Just searching around google and youtube Ive seen so many things that contradict each other and want to make sure I do things right. Cheers

 

[Jhn]

Thank you for the replies. I bought a Hozelock 3003 easyclear 3000 for my pond but havent even added water yet never mind fish lol Just searching around google and youtube Ive seen so many things that contradict each other and want to make sure I do things right. Cheers

Yes, it can be confusing, always better to under stock than push the filtration/size limits of your aquarium or pond.

 

[mant01]

Thanks for the advice, much appreciated

 

[Mmathis]

Agree with Mmathis, filtration is a factor, type of goldfish, as well. Also, in a pond goldfish will reproduce and your goldfish population will grow.

Never liked rule of thumb for fishkeeping in general. Better off, knowing and understanding your particular fish species needs. The idea when keeping pets is to keep them for their natural life span. Common sense tells me keeping a bunch of fish that get a foot long in a 50 gallon tank will not end well, w/o me majorly upgrading my tank size and filtration, eventually.

And, knowing and understanding how to monitor and keep the water healthy!

 

[mant01]

Yeah Ive got a lot to learn before any fish go in. I bought some Fresh Start to treat the water but still need to look into how to test the water and monitor things. Guess I'll be lurking around the forum and learning what I can.

 

[Mmathis]

Thank you for the replies. I bought a Hozelock 3003 easyclear 3000 for my pond but havent even added water yet never mind fish lol Just searching around google and youtube Ive seen so many things that contradict each other and want to make sure I do things right. Cheers

I’ve had my pond for 6 years. There is quite a learning curve involved. But one of the most important things I’ve learned is that......there really is no right or wrong way.....just different ways — long as you look at the science (and common sense) in whatever information you read, and don’t just blindly follow what everyone else does.

And, if it sounds too good to be true (as in many of the shortcuts you might read about), it probably is. The basic and most important part of keeping fish is to maintain a healthy water environment. If you poll everyone on the GPF, I’ll bet you will get dozens of people with positive pond experiences......and everyone of them (us) will be doing something different (basically the same, just different ways of doing it).

And, no matter how perfect you think your system is......there will be mistakes along the way. The successful ponders learn from their own mistakes, as well as from the mistakes of others. Just never get so cocky that you aren’t willing to listen and learn.

 

[mant01]

Thank you for the advice and help

 

[EricV]

I just looked up an online fish load calculator. It said for a 300 gallon pond you could have 15 fish inches. Not 15 fish, but 15 total inches, for all goldfish. We do suspect that these calculators aren’t 100% reliable, because a lot depends on your filtration system. Beyond that, I really can’t answer your question.

Well, maybe this..... If 20 gallons Is what’s recommended minimum size for a goldfish kept in an aquarium.....then add 20 gallons for each goldfish....15 x 20 = 300.

Anything that I see that says anything about inches, I immediately disregard.

The amount of waste (which is the limiting factor here) produced by a fish goes up 8x when the length doubles. The fish gets twice as long, twice as wide, twice as deep. Inches can only work if you assume some average size.

 

[sissy]

fish inside are not the same as fish outside .You have all kinds of weather conditions to deal wth and some can mess up the filter .Things like heat or rain and cold can and will throw off the balance of a pond.oh and Welcome