Backyard Aquaponics
A place to discuss aquaponics

We have about 40 Jade Perch all seem to be doing ok....... in the last month or so we have had 4 fish die they are about 10cm long....don't see anything wrong with them.
Our PH is about 7.4. We were wondering are we feeding them too much, so we decreased the feed so all the feed is consumed before next feeding due. But we have lost another one today
Not sure what the problem is....any ideas?

..
forget pH.. the Nitrites and Ammonia are the ones to be concerned about.

then, the lower the pH , the lower the injury from the Nitrites etc
and the inclusion of salts.. eg. Calcium Chloride, are said to help the fish and stop some of the nasties uptake..
What temperature?? any significant temperature swings

and check the gills of the dead fish - what appearance/color..
..
.

Probably temp related if they are small.

But yea need temp, amm and nitrite readings please

They are not small they are about 10cms long and the gills looked normal. Took reading on the 3/8/15 Ph 7.6 Amm .25 Nitrite .50 and Nitrate 3.0. We control the temp of the water it varies from about 14 - 18 degrees. So do we use the salts to lower the Ph if so how much and where do we get it from.....? We have noticed the Ph has been sitting above 7 for a while but not sure how to lower it....putting more water in doesn't seem to be doing it at all.

I'm with Charlie...

We can't keep Jades over here in WA, so I have no personal experience with them, but the reading I've done on them by Qld breeders and Qld Ag' dept' etc, would suggest 18C is the lower "comfortable" limit for Jades, at 16C they will begin to stress and be at risk of developing stress related disease... and 10cm is still a small fish, the smaller they are the more susceptible they are to cold related stress.

ok thanks Mr. Damage. we are looking at getting a electric heater that will keep the heat higher than what we are currently doing...we use a pot belly to heat the water that is coming into the fish tank we can get it up to about 18 - 19 degrees. Thanks for your help. Do you recommend any other fish that would be better for us...We live out west of dalby... We also have insulated the fish tank for winter.

CCbear got his Jades through winter and he is situated just above Brisbane, from a quick search his tank got down to around 11-13deg but they were very sluggish. He mentions that once it was down to 18deg he was only feeding small amounts once per week and below that don't feed at all. But he had large fish.

As MrD mentioned, 10cm is still very small fish. Id stop feeding but maybe give them a little on a warm afternoon maybe once a week or even 2 weeks. It won't be long till the weather warms again.

How much media do you have? From memory you have an IBC system? An electric heater will do nothing because the grow bed is like a massive heat exchanger and all will be lost as water passes through it. You can shut the bed off at night to reduce further cooling the water but I don't know how much that will help.

Its possibly a combination of over feeding, low temps and maybe under filtered.

Silver perch have a better temp range but they are very slow growing, about 2-3 year grow out. If you can get your Jades through Id stick with them. After this winter you will have a better idea how to control winter grow outs.

Just confirming Charlie's advice. Stick with the jades if you can.

I'm in northern rivers of NSW... about two hours south of Brisbane. I have some jades (about 25 cm) in an insulated and currently heated tank. In summer, they're much faster growing than my silver perch. The silvers handle the cold weather much better but my jades are doing OK this winter in water that hovers around 18.5 to 20... they don't eat much but they still spark up when the pellets hit the water and they look pretty healthy.