How Many Goldfish (480 Gallons)

[Acro]

I haven't kept goldfish in several years and I don't remember the stocking rules . . . also my situation is a lil different than a normal aquarium with traditional filtration . . . 

So, I have two 80 gallon stock tanks and two 160 gallon stock tanks in my garage.  I'd been planning on setting them up with individual aquaponics filters, but I realize it's a better idea to connect all 4 tanks (via PVC pipes) to have a grand total of 480 gallons in one system.  With this type of filter, water should be pristine. 

With all of the above in mind, about how many single tail goldfish would be happy in those individual stock tanks?  What's the guideline for something like this?

 

[Arctic Mama]

Well conservatively is say 20 gallons per fish is good, but many of us stock closer to 10 and do fine, if the filtration is well maintained and you know what you’re doing  

If I wanted lower maintenance I’d cap it at 30 fish or so. Can’t wait to see it when you’re done!

[koko]

On 12/23/2020 at 6:41 PM, Arctic Mama said:

Well conservatively is say 20 gallons per fish is good, but many of us stock closer to 10 and do fine, if the filtration is well maintained and you know what you’re doing  

If I wanted lower maintenance I’d cap it at 30 fish or so. Can’t wait to see it when you’re done!

 I have pushed my limits with my tanks before. The one thing to remember if you do push it, water changes, keep them going  

[Acro]

On 12/23/2020 at 9:41 PM, Arctic Mama said:

Well conservatively is say 20 gallons per fish is good, but many of us stock closer to 10 and do fine, if the filtration is well maintained and you know what you’re doing  

If I wanted lower maintenance I’d cap it at 30 fish or so. Can’t wait to see it when you’re done!

Thanks Arctic.  I plan to stock heavy-ish in order to feed the plants in the grow beds.

54 minutes ago, koko said:

The one thing to remember if you do push it, water changes, keep them going  

In a traditional tank, water changes are a must!  With aquaponics, from my understanding (and I've done, and continue to do, a bunch o' research), an aquaponics setup really does not require water changes.  The plants use the nutrients and return the water clean.  Of course, there needs to be constant monitoring, but in theory, even with goldfish, water changes should become a thing of the past . . . And I'm so excited for that!  It seems that many aquaponics systems are run with heavily stocked goldfish tanks, with very few water changes needed (maybe 1ce or 2ce a year, sometimes less).  It seems like magic but it seems to be true. 

[Arctic Mama]

@Acro the issue in aquaponics isn’t nitrates, it’s the redox potential and osmotic balance in the water. Mineral content. Water changes do definitely need to happen unless you’re regularly testing trace minerals and adjusting substrate and filtration additives as needed. They just tend to get too soft and acidic for goldfish without that. Commons are more forgiving with this, and with outdoor systems with ongoing leeching substrate. Fancies don’t do as well in terms of stability. I’ve only seen that fly VASTLY under stocked long term.

[Acro]

2 hours ago, Arctic Mama said:

@Acro the issue in aquaponics isn’t nitrates, it’s the redox potential and osmotic balance in the water. Mineral content. Water changes do definitely need to happen unless you’re regularly testing trace minerals and adjusting substrate and filtration additives as needed. They just tend to get too soft and acidic for goldfish without that. Commons are more forgiving with this, and with outdoor systems with ongoing leeching substrate. Fancies don’t do as well in terms of stability. I’ve only seen that fly VASTLY under stocked long term.

In my research the words "redox potential and osmotic balance" haven't shown up much.  It's late now, but I'll have to look into this, thanks!.  As for the mineral content (which is what I think goes along with redox and osmotic, I was going to add oyster shell and/or marble and granite pieces to leech minerals into the water.  I'm still working out how to balance everything, it's complex but so amazing!