Backyard Aquaponics
A place to discuss aquaponics

Would it be different in our case?

I bought 3 goldfish yesterday, roughly 2" long and with a 30 gal "fish tank" haha... funny lookin' barrel; wouldn't want to show my set up to a serious fish keeper (Is it hard on the fish if the tank is not see-through?).

Apparently, from lurking in other fish forums, I can only have 3 max then since "10 gallons per gold fish".

I don't know the ratio. Probably why I ended up with the amounts I've run with before. But as long as there is enough filtration and the fish have enough room to move without being stressed.

I just had 25 goldies in my 10 gallon quarantine tank for a month. They were fine. Duff is right about having enough filtration. I had to change out the water every other day since I don't have the tank on any growbeds.

Make sure you don't add pet shop goldfish to a clean system....they are usually diseased! I always treat with salt and melafix for 3 weeks.

There are big differences between keeping an aquarium and keeping and aquaponics system.
1- seeing through the tank is for the pleasure of the people looking at the fish, not for the benefit of the fish.
2- aquarium filters tend to be much smaller and meant to keep the water crystal clear for viewing hence the need to have less fish per water volume.

In Aquaponics, since the point isn't to display/look at the tank/fish but to grow food, we base our stocking levels on weight of fish in relation to the filtration. If doing flood and drain media (gravel or clay balls etc) we go with 3 kg of fish per 100 liters of media as a good max for a home system. (That would be around 5 lb of fish per 25 gallons of grow bed media or 1 lb of fish per 5 gallons of media.) Then you just need enough fish tank to keep the fish comfortable. for instance that 3 kg of fish could be in a 50 liter fish tank so long as the set up has a constant level in the fish tank (and some extra water in the system some where to absorb the water level fluctuations for flooding and draining the media.)

So your 30 gallons of fish tank if it is hooked up to 30 gallons of flood and drain grow bed could have up to 6 fish if you expect them each to reach a lb. If you only plan to let them get to half a lb, then you could have 12 goldfish in there.

I had 5 3-4 inch catfish in a 10 gallon aquarium for a couple months, they did fine, it was hooked up to 25 gallons of flood and drain grow bed and there was a 50 gallon sump to provide plenty of extra water for the flood and drain and buffering.

TC - you have hit it right on the head! I have had 5 (2 - 3" each) fish in my 10 gal aquarium for over 4 months before I added a GB. There is a member "Dusun Aroma" on the forum who has 200 tilapia in a 55 gallon barrel with just two half barrel growbeds.

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Confuzedd: It would be helpful to know if you are planning a grow bed and its size.

It is really best to have grow beds hooked up before adding fish. Those that have gotten away doing it the other way around, are either really lucky, or have some sort of bomb proof fish like common goldfish or tilapia.

Fully second that!

Plan system, get fish tank/ and or sump, fix grow bed, cycle fishless with Humonia till all levels look good - then add fish is what I would do.

Note that they were all stunted...... And we don't know how long they were in there for, they may not have got above fingerling size. Better to go lightly with stocking densities rather than dig holes to bury dead fish.

lol too late...

What happens to the plants BTW ?

My hobbyist AP system is finished and hooked up. The fish tank holds roughly 27 gals of water and the sump is 13 gals max. The grow bed is made from the other half of the cut barrel. If you folks think I'll need an additional grow bed I think I'll make them out of half-pipes and grow a bunch of tiny plants in them, or maybe grow plants in the sump and some in the fish tank?

Web4Deb, what kind of salt to use? Does it matter? Common iodized table salt from the super market? I saw some dude mention here "Sea 90" which is also good for the plants, but this brand seems like I'll have to buy it online.

Do you think I can just add salt minus the MelaFix into my actual AP to at least slow down the growth of the fish diseases (if present) to continue cycling? Because if I transfer the fish into a quarantine tank I'll have no ammonia source.

And sorry folks, I know everyone prefers fishless cycling, but I wanted to see fish swimming in my "aqarium" ASAP.

You can cycle with fish but it can be far more stressful for the fish and the people involved since you need to spike the ammonia and nitrite some to cause the cycling to happen but those spikes can be hard on the fish and if they get out of hand, they could kill the fish so sometimes water changes need to be done but water changes will slow the cycling process too.

As to salt. Iodized salt should be avoided since the iodine can inhibit if not kill the bacteria you are trying to grow.
Regular table salt also usually has some anti-caking agents that can cause some problems too, at the very least they might tend to cloud the water but there has also been mention that they could be bad for the fish.

You are better off getting sea salt. In many places the cheapest water softener salt or pool salt is simply dehydrated salt water, that would be the stuff to use, plain dehydrated salt water with no special additives or pelletizing agents or rust removers. I usually buy what they call solar water softener salt or solar pool salt. Usually comes in a big heavy bag.
1 ppt of salt is usually enough for protecting against problems with Nitrite. 3 ppt of salt is often needed to combat diseases for fish. Most plants are ok with 3 ppt though some plants are more sensitive to salt than others.

Okay, got it. I'll go to my local grocery stores some time this week and see what they have...

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In regards to how many fish in the fish tank.
If you under stock the tank, do the plants grow and flourish or do they just sit there and survive?

ie say u only put 1kg of fish in the 100ltr FT instead of 3kg.
Do you think there would be enough nitrates for the plants to flourish?

The water tests show 0 ppm for ammonia, nitrites and nitrates.

Would you keep putting more fish in?

This is where i'm kind of stuck.

I pretty much have a barrel ponic system using a 150ltr FT.
The plants just sit there and survive but none are actually flourishing like i see in other member systems
I have around 30 gold fish of around 3inches or 7cm.
Any suggestions?