Help - 5 dead fish :(

[Burnbrae]

Hi,
We are in the sunshine coast hinterland, and the AQ set-up (balcony kit from Murray) has been going since the start of Feb. We washed out the filter from the inside aquarium into the initial water to get the good bacteria happening. Plants went in immediately, with a couple of decent sized gold fish from the inside aquarium. We got a few silver perch during Feb from the local fish farmer, and got 50 little jades about 3 weeks ago. They have all been greedily eating and appearing quite happy until the last week. At first we blamed this on the nights getting cooler.

The initial pH was over 7, but that has drifted down over the last month. It has been 6.6 for the last week, but was 6.4 this morning. I have noticed that when I add some Seasol, the pH goes up for a little while, and that it goes down after heavy rain (of which we have had a bit the last week).

It was only after the jades were added that we actually started to see any readings other than zero for the amonia, nitrites and nitrates. This also corresponded with me harvesting the lettuce and bok choi, so there were less plants to take up the nutrients. The next day, I planted many more plants, which seem to be doing fine.

The readings for the last week have been constant, until today when the amonia disappeared.

Test last week today
amonia 0.25 0.0
nitrite 0 0
nitrate 40/80 40/80

When the nitrates hit this level, we reduced the food to once a day, and have stopped completely now. The fish are not interested in the food at all, and even the odd leaf that I drop in is ignored.

The water temp has been dropping - was 20 today.

I went out and bought some more seedlings and squeezed these into the grow bed this morning. i beleive that the recommendation for high nitrate levels is to add another grow bed, but we need to see if there is enough sun on this block to make it worth the effort. My tomatoes ended up with a fungus from not having enough sun (according to the guy in the plant shop), and the snow peas are not doing that well.

I would appreciate any advice.
The local fish farmer does not keep jade perch as he says they do not survive the winter here. As there are 2 dead silves adn 3 dead jades, and the water temp is still 20, I do not think this is the problem.

[Castaway]

What about air? You are running the pumps 24/7? Plenty of oxygen getting into the system?

[Burnbrae]

Yes, the air pump that came with the system is running 24/7. The water pump too is running 24/7. My husband has played with the overflow to stop it slashing all over the bottom of the lid - it runs thru another pipe with little holes drilled into it

All the fish are however congregating at the oppositite end of the tank from the pump and the air stones - which is unusual as they normally like the corner behind the pump.

This morning was also the first time that I have noticed a 'fishy' smell.

[fishfood]

Just grab a broom and give the fish tank bottom a scrub to make shore there isent a buildup of junk there Sounds like water quality problem how is the tests

[Burnbrae]

Grabbed a broom and opened lid to give tank a sweep. another poor little jade upside down almost on the bottom of the tank. Very little junk on the bottom - just a bit of gum blossom that has fallen in. Amonia is nil; nitrates are between 40 and 80 (I am not good with shades of colour); nitrites are nil; ph is 6.4; water temp is just under 20.

[aussieap]

Hi Burnbrae.
Have a read here
www2.dpi.qld.gov.au/fishweb/14076.html

Could be the night time temps getting below that 17C as per the article above.
pH should drift down in our ap systems. You will need some Eco Rose to buffer back up to that 7-7.5pH. You might get some 300 watt aquarium heaters. This will keep the a bit happier at nigh over the coming cooler months.

fwiw I have had small silvers down to 8-9C over winter. It is probably a local strain thing tho and the northern ones may not be quite as temp tolerant.

[Castaway]

Eumundi is slightly inland (about 20Km) from where I live right on the coast so it would have a greater night time temperature variation. I have 60 Jade Perch all doing well (water temp 24C) so the temperature variations are not so severe where I live. The last few days have been cooler and I noticed the fish ease off a little - but they are still actively eating. If I where you I would take a close look at what is falling down from the trees above into your system and seeing if it has some influence on the health of your fish.

[Burnbrae]

We are now up to 11 dead fish - 2 silvers and 9 jades. Very sad. all teh jades at least had round tummies - so not sure if they ate too much, if this is normal, or if it is a symptom of what killed them. All were floating in the bottom of the tank, belly-up - which I have not seen before in fish deaths in our aquarium.

We did a 1/3 water change and the nitrate level is now between 20 and 40, adn teh 'fishy' smell is gone.

We also took the time to pull apart the pump and clean it - had not been done for a couple of weeks - amazing how quickly it gets yucky.

I am not keen on doing the heater bit - mainly cause a couple of years ago one went bad and we boiled all the tropical fish in the small aquarium inside. But I do realise that it will take a fair bit to heat the AP tank. But then I am not keen to lose any more fish. The silvers come from a guy about 2km from here, so I expect they should have been fine temperature wise - but then I expect a large pond would not get as cold as a fibreglass tank.

Yes, Castaway, I have been wondering if gum blossom is a good thing for the fish. I know they eat it, as until this week, they kept the bottom of the tank clean from it!

I am hoping that there are no new fatalaties in the morning.

[GaryD]

Stop feeding immediately. Jade perch will continue to eat past the point that is good for them. Stopping the feed will also assist with any water quality issue you may have.....although I can't see any issue with any of the readings you've provided so far.

[Dufflight]

Trees droping things in the water can affect your fish. Not sure about gum blossom, sounds like a native. Some of our trees have a habbit of protecting there area with toxins.

Also are you salting the water. Sea salt 1 to 2 ppt.