Aquaponics - Fish death

It's horrible when you lose livestock. It's even more horrible when you have no idea why.

I found this guy on the concrete. Not such a good place for a fish.

It doesn't look like it was dragged out by a cat or anything. And, in fact, looks in pretty good condition.

Apart from being dead.






The day before the fish death, I added a small pinch of potassium bicarbonate to my system to see if it was a lack that was causing my baby spinach to yellow.

Food grade potassium bicarbonate is an additive that people growing aquaponically have been using for  ages. It's used as a supplement if there are insufficiencies in the fish feed. It's also considered safe to add to your system in the doses I used.

I find adding anything to my system to be a really scary pastime, and would prefer not to ever add anything. In this case it changed the surface tension of the water slightly, and created bubbles.

The bubbles collected around the pipes and looked a little like the bubbles you see on the surface when fish are distressed.

A little like those bubbles but not quite the same. These were slightly looser and bigger than the ones I saw during my fish from the poison bush.

But similar enough to make me uneasy, especially when the next day I notice that one of my fish is missing.



I still have no idea what the problem was, and I'm told the bubbles are normal when you add potassium bicarbonate.

It's possible that the fish just had some other issue.

All the others look as happy as they always have.

I have no idea what caused it, and given the level of the expertise of the people recommending I add potassium bicarbonate, I doubt it had anything to do with it.

I hate coincidence.

And problems I don't know enough about to solve.








And then there were ten.






.

Aquaponics - Poison plant

It seems I may have been poisoning my fish.

After the last fish death, which also occurred just after rain, I started to think that perhaps the rain was splashing off the surrounding environment and getting into my fish tank through sneakiness.

I looked at all the possible things the rain might be able to occasionally transfer to the fish tank from in a strong wind, and there didn't seem to be much chance of any transfer to the fish tank from anything other than this shrub.

The shrub turns out to be viburnum tinus, and sadly it seems, is toxic to fish.



So right now I'm in the process of moving the experimental system to pastures less green.

At the moment the fish are in a plastic tub, floating in the fish tank,  getting used to their new water, and its new temperature.

I realize this has not been the first time I've felt I had the solution, but hopefully this poison plant might mark the end of the fiasco that has been my first batch of aquaponics fish.

There are eleven silver perch left out of what turned out to be twenty two.

Interestingly, as a result of seeing them in a container, I discovered some are twice the size of others.

Aquaponics - Hot house

I did a backyard version of an autopsy on the fish that died in the (almost hopeless) hope that the fishy's gizzard would be full of staples, bolts, or something easily identified as the culprit, but it turns out dead fish aren't filled with industrial fasteners, but are in fact just filled with fish guts.

I covered the grow bed in some plastic in the hope that it really is rain that's causing my problems, and also to make an aquaponics hot house. I started with three bent piece of poly pipe (I new all those 5 ft lengths of poly pipe with holes in them would come in handy eventually).

In traditional Australian fashion, I attached everything with wire.

Then covered the entire thing in plastic. I made it so there was no wire on any section that may get condensation running off it. The last thing I need to do Is introduce too much metal into my system. I also made it so that the condensation would run onto the ground rather than back into the grow bed just to be safe.

I got it up just before the rain started. It looks very stormy so I think it was just in time.

The sad thing is, even if this solves the problem, I may have already damaged the gills of my fish. From what I've read, these issues can show up many days down the track.

Even if this doesn't solve the problem with the fish, the plants will love it, and it should keep the system a bit warmer in this stormy chilly weather.

Aquaponics - Keeping good records

I had another fish death today, and it was after some rains. I had a niggling suspicion that the last one died after rains as well. There have been a lot of deaths and I now only have twelve.

I got some data from the bureau of meteorology to check against my records of fish deaths. Unfortunately, and foolishly I don't have complete records of deaths.

I had planned a good news aquaponics story today as the fish were all looking good, and feeding well over the last few days. I thought perhaps I'd put this fish death business behind me, so I figured I'd take some video to show how vigorous and healthy the fish seemed. I didn't notice the dead one. Not so vigorous.

Not recording those previous fish deaths was really crazy. My excuse at the time was that there was no point. It turns out keeping good records is incredibly important. If I had done so, I might now be certain of the cause of all my woes.

Here is a graph showing what I think is a correlation between my potential pH changing events, and my fish deaths. Fish don't like sudden changes in pH and a change can be fatal. Rain could have the effect of lowing pH, but I'm not sure if it could lower it, and then have it recover to normal levels before I did my pH tests. I'm also not certain if a short term change would distress the fish. After all, rain is pretty normal stuff in a fishy world.

B,D, and F all show strong correlations between rain and fish deaths. Rain would have a lowwer pH than my fish tank water.
A shows fish deaths in a dropping pH environment. Not due to rain, but due to the normal action of the nitrogen cycle. G shows the effects of the addition of shell grit to the system as a pH buffer to attempt (successfully) to buffer the system against sudden pH shocks.
C and E show significant rain events that may be responsible for my un-recorded fish deaths. Poor science I admit, but it was around these times that I lost fish, and I'm running out of other ideas. Did someone say "grasping at straws" ?

A,B,D, and F, all show potential pH lowering events. Sudden drops in pH can cause fish deaths. All my fish deaths I have on record strongly correlate to pH drops, or potential pH drops. Thats good enough for me to take action on.

I'll build a cover. It wont do any harm If I'm wrong.

On a lighter note, here is the happy fish video.

Aquaponics - Sick fish

I had another fish die this afternoon, and one is in my kitchen in an aerated slightly salted bath, trying to get cured.

It has some fin damage to it's tail and, it has what appears to be mould on its back.

All the water tests report normal, so I'm researching all I can on fish disease. Actually there was a slight spike in nitrites (.25) but I think that was due to the dead fish.

Busy - what I need is a fish expert.

[edit from the future - All these woes ended up being part of an ongoing problem with me poisoning my fish with rainwater run off from a common garden plant which is highly toxic to fish - http://120thingsin20years.blogspot.com/2010/07/aquaponics-poison-plant.html]

Aquaponics - Exclusion zone

It's said that a picture paints a thousand words. But I'm confident that I could have described this in under two hundred words.

I had another silver perch commit sashimi yesterday. I'm not certain if it was due to being caught up in the original ruckus, a new ruckus, or some mystery problem that I'm yet to discover.

I built a new and hopefully improved exclusion zone around the pump made of a soft drink bottle with some holes drilled in it. There. That took only ten words. They are already trying to defeat my new anti-fish security system as I type.

I get the feeling they are desperate for cover as they seem to be trying to burrow behind and under everything they can.  No doubt they are distressed at all my mucking about in there. Tomorrow I'll add a terracotta pot or something suitably non-toxic as something to hide in or under. I think they have had enough for today as I'v had my hands in their world for the last hour or so trying to block all the entry points to the pump.

This episode has raised some issues with regards my design for the bigger second system. I'll need to figure out some way to make the powerhead safe.

I also discovered as a result of a head count that I actually took delivery of twenty two silver perch, not twenty.

Aquaponics - Fish deaths

Fish deaths

extra sad