Backyard Aquaponics
A place to discuss aquaponics

Good point. I'd probably harvest them as well if they were big enough, if not then they may need to be grown out in a seperate system on antibiotics and other such nasties and fed to the MIL

[quote]having said this we never know what the suppliers have been pumping into their fish. we can only control our own practices. quote]

Again, Good point. Though I would be more worried if I was buying mature stock and not fingerlings.

Personally IMHO

I would try a herbal solution first, no guarantees about these though in vet medicine (humans are well documented).

I'd try antibiotics next as these cheifly act by destroying the cell walls of bacteria, this means they can not funtion as a living cell any longer and die. Fish and humans have no cell walls in their cellular makeup therefore are uneffected by their actions. Were animal life is effected is the colonies of bacteria that inhabit the gut. A closed system may be effected by the circulation of excreted antibiotics especially its colonies of bacteria.

I agree the fish should not suffer and a chem solution or destruction I would chose as the last option.

Melafix could be worth a try. I once bought the pond version - much bigger bottle so much better value. Got it from Ageofaquariums I think.

If you did this, you would want to isolate the fish into as small a tank as you could to reduce the amount you needed to use.

the problem is that the disease may have infected the whole system.

in aquaculture they would treat the animal and then the tank. this is simply not possible in aquaponics, unless you want to go back to point one.

if you treat the fish with antibiotics their immune system is suppressed and they struggle to fight off any introduced nasties. if you don't have absolutely sterile tanks then you gonna have problems.

in ap its almost essential to develop the immune system of the fish so that they can fight off these nasties. imo the way to do this is to create as diverse a biomass as possible in the tank. it will create a harmony which will stabilize the system.

thats the reason i asked if you dechlorinate as i suspect chlorine puts the balance out of whack.

i may be over analyzing and the solution may be simple. just want to cover different angles.

i think the spice is worth a try if you can't identify any other factor.

Your right BF, we dont know what our fish suppliers have treated their eggs and fingerlings with. I know of several fish suppliers here in WA that treat their fingerlings with Formalin and/or Malachite Green both of which should not be used on fish for the table. Your supplier may not use either but I bet he uses hormones to to get his fish to breed!! Australia is way behind the US in this area as there is no legislation in regard to what can
or canot be used on fish bred for the table. I know that in the US Malachite Green is banned and fish treated with hormones for use as a spawning aid canot be sold as food fish!

As for the fin rot the bacteria that causes it is present in most waters. An outbreak is usually brought on by either stress, trauma or poor water quality. Overcrowding can cause stress particuarly as the fish you have are of a larger size and most probably came from a pond and are therefore not used to living in such a confined space (is this the case?). Your other tank with the fingerlings although living in the same water are used to living in a more confined space and therefore are not stressed.
There is no point in treating the fish if the circumstances that caused the stress remain, ie the overcrowding. The best bet would be to reduce the number of fish in the tank and see if they improve. Adding salt or antibiotics dosent seem to have a great effect on curing fin rot from my experience.

good call troutman.

i had wondered about injection hormones myself. from what i gather most breeders use the technique.

i don't think its as bad as some of the other chems but where does one draw the line? i guess at the end of the day its about producing a healthier alternative to whats available commercially. i'm sure a hormone bred fish grown out in an aquaponic system would be far better for you then one bought of the shelf. they don't need to tell you how the fish is grown do they?

i don't think anyone has bred a silver in a tank without hormones yet. at least thats what i was told.

i only know of 1 person who breeds silvers in dams. the rest inject in tanks.

while i think of it. another factor that is impacting on disease resistance is inbreeding depression. when relatives breed with each other you have problems. i imagine this is a problem in the aquaculture industry. how many breeders actually go out and catch new brood stock? i doubt many. when pond bred then i imagine this is harder to control then in tanks. i know there is legislation in place in QLD that only allows certain barra stock to be used in production to address the issue.

i may be going way off track here but feel this thread has brought up some important issues that will need further attention.

Hi BF i made a mistake with PH retested bluelab instead of chemical and reading is 5.4 have lifted to 7 so far all is ok not all fish are sick just a few
and only in that tank i think TT may be right the larger the fish the more stress .
jim.

Hi Tm i think you may be wright about hormones i took a sick fish [belly up] and put it in the aquarium on its own no sign of any problems after 2 days it is nosing around head down on the bottom of the tank now it is brand new,i fished another one out [belly up] no signs of infection but belly looked like it was going to burst put it in with the other one but no1 did not like that it chashed it all over the place head butting and trying to bite so after 2 days no2 died i wonder why the fat belly.
Jim.

BF Tank water ph7 ec0 very good.
jim

hi TT i think you hit the nail on the head i think stress and lo ph did not help.
Jim.

hey Jim, good to see things are working out, particularly after the drama with the heavy rainfall washing nasty stuff into the system last summer. Bout time the AP gods gave u a break I reckon!

hi TT i think the heavy rainfall was the problem that F&F had.
Jim

depending on the antibiotics used they might be exactly the same as is used in humans and other animals. I would not rule these out especially in an isolation tank. but that is just my 2 cents

That's a good point Nick. Funny how we will take these pills ourselves, but cringe at the thought of eating a fish that may have been exposed to them

Its important to remember that the antibiotics (or herbal remedy) you use to kill the bacteria on the fish, may also kill the bacteria in the biofilter. My microbioogy is a bit rusty, and I couldn't tell you about gram positive, gram negative etc and what kills what. Someone above was right, that the remedies used in aquaculture wouldn't always work in AP, but not just because we want to eat the fish. Unless you can isolate the fish into a quarantine tank I would be reluctant to treat them with anything except de-stress strategies.