Backyard Aquaponics
A place to discuss aquaponics

3 fish died yesterday and then another 4 overnight (baramundi). Looking at the live ones, some appear 'ok' and some are looking sluggish with a white pale appearance. I have read as many of the past post as possible and have really confused myself. I thought with the establishment of a new system Ammonia and nitrites were supposed to spike to start etc. I have never heard anything about adding salt before, and find it difficult to find out why my kids are sick; let alone fish. So where do I start?

Thanks Jane

Start by posting your water test results (ammonia, nitrite, nitrate, ph) and also water temperatures. Without these, it will be hard for anyone to tell you what possibly is the issue. Although I did recall that you are located in warmer conditions, hence aeration could be an issue for you.

As the water gets warmer, there is less dissolved oxygen available in the water, hence you will need to provide more aeration.

Low concentration of salt provides freshwater fish with some protection towards disease/infection. I usually salt my tank to 3ppt (3kg per 1000L of water) if I introduce new fishes.

Start with a water test and stop with the feeding.

Yep, ivansg and TCL are right - without the test results we're basically guessing in the dark. Photo of the system will also help.

If you don't have a test kit, make sure you've got aeration in the water and then get on the phone to Faye or Joel and get one sent up.

Okay here we go
Test results 11/11/10 07/11/10

Ph 7.6 7.6
NH4 0.50 1-2
No2 2 5
No3 160 5

Sorry, dont have a temp tester.
Haven't fed this morning. Just checked: another one has died and about another 5 are pretty close. They are really pale. When they die they are resting on the bottom. Had a really hot windy day yesterday, blew alot of "crap" into the water, dust, leaves, seed pods and seeds and what looks like bits of poly foam.
Hope this helps. 1000lt tank with 2 grow beds

Jane

What is your pumping schedule like?
If you normally pump with a timer for flood and drain, I'd just run it constant for the night and test again in the morning. The ammonia and nitrite are high and with the high temps you have been having, that is hard on fish.

Do you have supplemental aeration?

What is your source water like? Is it scheme water, well water, or rain water? What is the pH of it once the CO2 is bubbled out? If Scheme water, what's it treated with and do you have a barrel of water prepped for water changes/top ups?

Asking all these source water questions since the answers will be needed before you should do water changes. I normally don't advise water changes during cycle up but it also sucks to be killing fish. Hopefully some one closer to you with Barra experience will take a look at your test results and the answers to the questions about your source water and advise you about next steps.

Have just spoken to the supplier and he believes they have nitrate poisoning. They need salt,
off to the shops I go

When Barra get to hot they go a real white-ish pale colour....grab a cheap temp gauge whilst your at the shop

Must mean nitrite - nitrates have to get to incredibly high levels before they start affecting the fish.

How many fish do you have.... and water temp readings are a must....

You can salt (sea salt or even pool salt) ... to 1ppt to mitigate against nitrite poisoning... that's 1kg of salt per 1000L...

I'm almost certain your problem is lack of oxygen....

Salt and turn your pump to continous flow for at least 24 hours... and don't feed...

Yes, as CD said. It is probably nitrite. Nitrite poisoning can be noticed by the blood of the fish turning brown. Of coz you can only confirm this on a dead fish...

But according to what everyone has already said,
1) Get yourself a thermometer. With barra it is important you keep water temperatures above 20degC constantly.
2) Add salt. This mitigate against nitrite poisoning.
3) Change to constant flooding. This helps with filtering the water more hence reducing ammonia and nitrite levels, hopefully, and also add aeration.

Thanks to everyone. Hopefully, by following everyones advice, I have limited the fish loss to 14.
I put the tank on continuous cycle and added salt. Unfortunately I haven't been able to buy a temp tester yet but next time I head off to the big shops I will. They are completely different looking fish this afternoon, so once again, thanks for your help.

Jane

Do you have any supplementary aeration Jane, other than the return from the grow beds... i.e. an air pump???

If so what size... and how many fish do you have??

Now I have 46 Baramundi fish, advanced fingerlings. They have to be about 10cm. I have 2 aeration pumps purchased from BYAP, which I was informed should be enough, but I do need to purchase another one for the back up water tank, so I think I will get another for the tank as well.

Do you have a link to the air pump