Backyard Aquaponics
A place to discuss aquaponics

Hi All,

First post here. I've had an AP system for around 3 years now and I have got my first fish disease.


From searching through here I found a PDF document from NSW DPI, and the disease I believe my fish have is Saprolegnia parasitica.

I know how and why Silver Perch get diseases and is most likley from being stressed, low PH etc and I am currently "salting" as per the NSW DPI PDF, but my questions are.

1. Is this disease terminal for my fish? Do I need to get rid of them?
2. Will the disease affect my plants. Can I still eat them?
3. I'm prepared to cull the fish and start again (sadly), but not sure how thoroughly do I need to clean the pond (1000L) and do the GB's need cleaning, do I get rid of my plants?

I may be over reacting, but want to be safe because it is a disease that I know very little about.....


I have photos if needed...

Thanks.

Saprolegnia is a fungal disease, the fungus is ubiquitous in freshwater aquatic environments in general. If you maintain high water quality and avoid stress by doing things gradually you may manage to bring the fish back to good health. You don't have to get rid of the plants, they won't be affected. You don't need to start again. See how it goes with the salt.

Good luck

I've often seen it on an occasional feed pellet that ended up in the ST on my small system, but the fish have not been affected. As Danny says above, it is everywhere, so it isn't necessary to clean your system and start again.

Salting is a good start. What is your water pH and temperature range?

Thanks for the replies.

I live in a cold area around Jandakot, WA. The water temp has been around 10 degrees, but its getting warmer since its now spring.

I have been struggling to keep the PH up for awhile now but now have it under control with advice from a local supplier. I believe the cold temps and low PH are probably the reasons.

I have been salting for a few days now and havent lost any for 24 hours so looks like its helping. Though my lettuce is looking a little limp from the salt.

Im more worried about the long term of the SPs health as I do plan on eating them.

Has anyone eaten their fish well after a fungus/disease breakout??

I had it in my perch. Salted and only lost a couple of fish. Veggies were fine and I've had many good meals of fish subsequently.

Not sure why you keep salting. Salt doesn't break down so once you're at desired level, you can stop.

Sent from my Pixel 3 using Tapatalk

Thanks for the reply and good to know you have eaten the fish after...

When I say salting for a few days i mean i haven’t done a water change yet.

Not sure why you would want to do a water change. Seems pretty common for people to run salt in the system full time. Apparently acts to assist with the fish staying healthy. And doesn't affect most plants, things like strawberry don't like too much salt.

My first lot of trout got affected with some sort of fungal problem which made the skin look like it was peeling off. Looked pretty bad, not a good beginning. I salted to something like 15ppt in sheer panic. This was back in the ‘test and react ‘ days. Celery loved it not much else I was growing though. A couple died but the rest cleared up then also died but for different reasons.
They tasted fine. I’m pretty sure I didn’t do a water change either. It did however give me a good reason to have a hospital/quarantine tank. I haven’t had an issue since.