Backyard Aquaponics
A place to discuss aquaponics

Hi people,

long time reader new poster.

Have been succussfully growing silver perch in my aquaponics however, introduced some new fish last week and seem to have a disease outbreak. Been reading all the stuff online however! finding something resembling what i have for sure is a problem!

Symptoms:

fish tails especially very ratty and appear to be bleeding
spines very exposed on dorsal fin and appear to have white edges in tank
one fish has white fuzz on tail
one or 2 fish very lazy
one or 2 fish have slight white marks to head when underwater

with new fish being introduced i expect them to be off their food.


the system is currently salted to approx 1.5 to 2 ppt as i have had a nitirte spike in the last few days

fish are very liveley when caught in the net and have a good slime coat.

had a mass death while on holiday a few weeks ago. was gone 4 days and the battery backup only lasted 2 so the fish died. re booted the system and levels recovered (ammonia near zero just taking a while to dispose of the nitrite.)

accurate diagnosis and treatment plan would help. if im going to kill my plants then ok. ill harvest now. However i have been wary of advise from many aquarium places as i dont want to kill my bio reactors.

the system relies on dwc and nft. no grow beds. swirl filters and bio reactors do the filtration

any help appreciated

Welcome to the forum. Sorry to hear about the fish problems. It sounds like a fungal problem (fin rot) but I suspect there was some aggression and stress with the addition of your new fish that allowed it to take off. The ones with white marks on their head could have Ich https://en.wikipedia.org/wiki/Ichthyophthirius_multifiliis - treatment in AP usually involves using higher concentrations of salt. Whether this will kill the plants depends on what you are growing and how high you have to go with the salt concentration. I don't know that anyone here will be able to tell you for specific plants but it's possible. I know it's tough to get good pictures but give it a try and see if you can post some pictures. Do you see any flashing behavior where the fish rub their sides against the bottom (indicative of a parasite like Ich)?

well,

sort some local advise from several aquaponics shops.

i highly recommend everyone avoids the aquaponics shop on warton rd canning vale! Asked the guy there about fish treatment and he had no idea!!! have been in there several times for parts and dumb founded him! zero understanding about bio filtration or water hardness. says i must be a difficult customer. never going there again!

went to my usual supplier,

he recommended treatment with Pimafix (all natural)

went for a second opinion,

they recommended tri sulfa tablets.

well i decided to conduct and experiment.

the 3 sickest fish (the easiest to catch) were removed and placed in 100l tank airated where they were dosed with pimafix to the recommended dosage (5ml per 40l of water to be repeated every day for 7 days)

the remaining 3 were dosed with tri-sulfa at one tablet per 40l of water (25 tablets to my 1000l setup)

after the first 24 hours all fish surviving and looking better in their behavior.

fish in 1000l tank left as is.

3 fish in 100l tank water flushed as no filtration currently hooked up and re dosed as per instruction.

6 hours later all fish dosed with pimafix DEAD!

3 fish in main system seem ok.

have been trying to upload images but the file size from my iphone is too large for this page to support

You may have a combination of a number of issues Simmo.

First things first. The recent Ammonia and/or Nitrite spike may have caused irreparable damage to the fish. They can die two or three weeks after such an event, no matter what you do.

Or, even if the Amm and/or Nitrite didn’t reach levels that could cause irreparable damage, it may have been enough to stress them, and stressed fish are very susceptible to disease.

As far as fungal and bacterial issues are concerned, IMO a salt treatment of both the fish and system is the best option… or possibly even Condy’s Crystals in difficult/extreme cases.

I would remove the fish to a very well aerated treatment tank, salted to 10gm/Ltr. In the meantime I would salt the main system to 6gm/Ltr, then add the fish back into it after 3-4 hours in the treatment tank. I would then do small, partial water changes every few days over the next few weeks, to get the salt back down to a level suitable for plants.

If it is actually Ich the fish have, then it’s not a disease, it’s a parasite, and very difficult to eradicate from your system. Even if you remove the fish for a short term treatment, when you return them to the main system there will most likely be Ich tomites that have been laying dormant waiting for a host.

With Ich you need to break the life cycle, which requires the removal of all fish and possible hosts from the system for a certain period of time, which varies depending on water temperature. Without a host the tomites in the system die off after a while.

P.S. The "Aquaponic shops" that sold you these solutions sound more like Aquarium shops to me. An Aquaponic shop would be very reluctant to recommend such products, if at all... Salt is your friend, it can fix just about any fish disease issue... those bottled solutions fix aquarium shops bank accounts.

Cheers for the advise,

would a salt bath for new fish being introduced into the system be an option prior to being added to the main tank?

The silver perch i have been growing were not raised from fingerling and were caught from a lake in a local estate.

laugh if you will but there are certain water bodies near me with silver perch even murray cod that silly persons have released into the waterways! While i condemn this i do try and do my bit by eradicating them from the local waterways and save 2 years on my grow out times.

Hiya Simmo, I always quarantine new fish to my system and have a dedicated hospital tank for this purpose. I have had a fungal issue brought in by fish from another system prior to having a hospital tank. Salting the system as mr damage says sorted the problem out. No fancy expensive chemicals just pool salt and patience, I only lost one fish and I put that one down.
There are only 2 AP shops I trust and use, Cheildys and mr damages'. They both have specialised knowledge of AP and also run their own systems.
Good luck with your system keep us updated.

Aww shucks... I'll put your carton in the mail this morning Skeggley!