Backyard Aquaponics
A place to discuss aquaponics

What does flashing mean?

(I've heard of men in raincoats etc?)

It means your fish have itch and are turning to rub their sides on the bottom of the tank, then showing their white underbellys, a flash. Salting boosts their bioslime and usually fixes the problem

Ich parasites attach themselves under the scales of a fish.... salting causes the parasite to detach... and die...

Thanks Mantis and Rupert.
Seems so simple, once you know!

I'm looking into aquaponics in the UK, have been looking at fish this evening, found this site http://www.livetilapia.co.uk/products.html am I right in thinking that's the same misinformation you mentioned in this post a couple of years ago?

Very probably.... but Tilapia are a very forgiving fish and can be stocked at greater densities than most other fish...

It's still not good practice though... and the recommendation/information alluded to... is just not based on any sound principles.....

Yeah, not great information... I still wonder why people want to grow tilapia in the UK, you will need to heat water all year round. I'm a big believer in growing a fish for your climate and keeping energy costs down.

I agree. Heck, I don't even want to grow tilapia here in Florida USA and we are sub tropical and would only need to heat the water perhaps 3 months of the year (but those being my best growing months of the year for veggies, I want fish that will be willing to eat well those three months!!!!!)

WHY do people always want to put outrageous numbers of fish in a tank, I'll never understand. I had some one here insisting that 500 tilapia in an IBC tank was what he was told!?!?!?!?!?!?!? NOOOOOOOOOOO And he was talking about a single IBC system with the top as the grow bed!?!?!?!?!!
OK Buddy, how bout stocking say 12-15 fish in that if you actually want to grow them out and eat them before you kill them all.

This thread is extremely helpful! Please help a beginner and indulge me some clarifying questions: different species' stocking rates reflect... larger size of catfish at harvest?

And please help my math-challenged brain to see if I'm following : for an IBC tote, can I infer/extrapolate correctly that this guideline recommends a FNG like me could stock at most up to (after cycling, I get the caveats):

• Catfish: 275 gallon IBC= 27 catfish, with (20 gallons X 27 cats) 540 gallons of 12" deep grow bed = (540/7.5 gals per cubic foot = 75 square feet of grow medium?
  
  
• Tilapia/Bluegill: 275 gallon IBC = 55 tilapigills, with (10 gallons X 55 tilapigills) 550 gallons of 12" bed = 73 sq ft. grow medium?

Am I close?

Probably close enough, provided you have some means of controlling water level fluctuations.

(If you were to flood 75 cubic feet of grow bed from a 275 gallon fish tank, you would not have enough water left in the fish tank for 27 catfish.)

So if you are trying to go for max stocking of the fish tank, you really need to make sure you understand Constant Height In Fish tank systems with the addition of a sump tank or some other means to minimize water level fluctuations in the fish tank.

I also personally wouldn't use an IBC as a fish tank for channel catfish if you are planning to grow them out very big, I think of 300 gallons as the minimum amount of water I would want to grow out large fish in. A fish that can get to 2 feet long in a fish tank that is only about 3 1/2 feet wide just seems a bit crowded to me. That said, I do know people who have grown channel catfish out in IBC tanks but I expect they probably harvest between 3/4 and 1 1/2 lbs.

Thank you! Definitely planning a Chift-pist with sump. Maximizing stocking is not a primary goal for me, hoping to harvest fish over time and I've always felt medium-sized cats (1 to 1.5 pounds) make better eating than giants though those are wild-caught.

Likely would use a blend of cats and tilapia, hoping that would help stagger the harvest?

And on that size consideration, would a different tank style better support a larger fish? Say, a 300-gallon Rubbermaid stock tank (shallower and about 6' oval)?

It would necessitate Chop-2-style plumbing with that low of a tank, which I know is like voting for the Taliban around here right?

In a sump system, I have a 1/2" line from sump going to my FT. The sump is appx 225 gallon and the FT 200 gallon. How much water should I pump into the FT each hour? I have a 2" drain back to the sump along with 3 appx 4 x 4 GB's and some towers. If I "open up" the fish valve, I lose pressure on my towers, and 24 sq ft DWC bed, which I have turning over once per hour. I also have 10 tilapia in the sump and appx 30 in my FT. Growth appears good, PH is staying on the high side 7.6- 7.8, in spite of numerous additions of PH adjusted top offs

We never noticed a flavor problem with bigger catfish in our systems, of course our fish are leading a luxurious lifestyle getting fed a balanced diet and all so they get bigger faster and mature faster than wild fish so while a 3-6 lb fish might be only 1 1/2 years old (one year of living in my system) a wild caught fish of the same size might be 3 or more years old and have had a lot more time to be eating less than tasty stuff. That said, many people seem to prefer wild caught catfish (that catfish place won't buy farmed catfish) I guess they think they have more flavor. Most people who complain that catfish tastes muddy would probably prefer the totally bland taste of aquaponicly raised catfish.

Chop 2 works and allows more flexibility of layout and the sump basically winds up acting kinda like a settling tank which I suppose you could vac out if solids start to build up much.

I actually prefer a 30-36" deep tank if it can be found since the stock tanks are so shallow that you really can't have that much water in them and still keep your fish from jumping out.

As to putting catfish and tilapia together in the same tank, they can live together fine, however, I would probably avoid that just because trying to catch a tilapia is likely to beat up the catfish which are slower moving and rather prone to net injuries since they don't have scales to protect their skin.