Backyard Aquaponics
A place to discuss aquaponics

Hi
Just wantIng to know if anyone could help me I have lost 9 fish in 3 days all small one 50-80mm all my big one are ok.
I have a blanket weed problem that has flared up again in the last week or so and I cleaned the tank on Sunday and there is still lot of algae floating.
The only other thing is that I used a piece of Batu decking as a stake for a tomato plant it is untreated but maybe it is leaching something, I have removed it today.
The silver perch went of there food early in the week and the first time they have eaten is today and they are turning on their sides and rubbing themselves on the bottom of the tank
There were 3 fish swimming on the surface tonight which is not normal for them.
All the tests are normal ph etc
Any ideas would be great
Adam

I wouldnt fuss to much on one stake. Dam, I accidently tipped petrol in one of my fish tanks (dont ask).
Im not sure of your system, have you posted pics of it? If the SP are flashing you will need to salt, I would run 3ppt and make sure you have removed all the dead fish as they will stress the others out and cause further probs.

Yep, as Charlie says, salt the system if you haven't already. Is it a 2000L tank? If so, salt with 6kg of salt.

What's the salt helping with?

Flashing.

oh, I missed that part...

I think salt is a short-term treatment option, but if this problem persists, I would try to investigate if there's another cause.

I was thinking the algae and fish dying might be more due to dirty water (or by aquaponics terms - too much nutrient). Flashing is a symptom of chemical irritation too... but you said tests came back clean?

Adam, does that include phosphate test? Phosphates can lead to an algae problem. At night, it can lead to O2 depletion (algae and plants release CO2 in the absence of daylight for respiration). This may stress fish out and lower their immune system and the rubbing may be due to parasites (a common problem for overstocked tanks).

Just a thought. I know Aquaponics has a different perspective and someone already warned me to drop my 'bad habits' and 'prejudices' I have from that, but I would be concerned with water quality first.

Salt is pretty benign though and I wouldn't have a problem trying that first. Just keep a look out and take water quality into consideration. You may be overfeeding too.

Could be Ick. Have the fish got any white spots on them that look like grains of sugar?

http://en.wikipedia.org/wiki/Ichthyopht ... ultifiliis

Fish all look to be normal no spots of any kind
I do not have a tester for phosphates
Do we just use pool salt from the hardware
Adam

Yes. Use pool salt.

You can also use water softener ... just make sure it's sodium chloride and not potassium chloride.

I don't know about tomatoes... but the salt could effect some plants. You could also do a salt dip on each fish.

Again, it might work and even provide relief, but if it reoccurs in a short time I would check to make it's not something else. Healthy fish in a healthy environment should not need regular treatment.

Also cover the tank, blockout the sunlight and the algae can't grow.
+1 for the salt. Fish don't like big changes it causes them more stress.
Can you post a picture Smallbrook?

Strawberries dont like salty water but everything else seems to be fine. My system has been at 3ppt for over 6 months and havnt had any fish problems to date.

Did not loose any fish overnight or today, I added the salt this morning and they feed pretty well tonight so we will see how it goes I guess
Thanks everyone
Adam

SB, well try testing the pH of your water just before sun down and also just after sun rise. Algae could contribute to pH fluctuations as it releases carbon dioxide into the water during the night (I think) hence making the water more acidic. If the fluctuations is quite big, it might affect silvers are they aren't to happy about pH changes. Also in the night, algae takes in oxygen, so the oxygen levels in the tank might drop, make sure you have added aeration going as well.