Aquaponics - Ich

Ich, or Ichthyophthirius multifiliis, is a protozoa that causes all manner of fishy itchyness. What a protozoa is, is anybody's guess. But it has an interesting life cycle and is some kind of parasite that likes fish.

Best practice would be to quarantine any new fish for a couple of weeks before adding them to your system. I aspire to second-best practice. But this isn't currently an issue because I'm not adding any new fish. I just thought you should know that.

Its a fair bet that ich colonize most aquaponics systems, fish tanks, rivers, and wherever fish hang out. Normally healthy fish seem to cope with the odd parasitic occupant, as long as the fish are not stressed, are well fed, and are generally otherwise healthy and happy. When fish are not so healthy they find it a little harder to fight off infections, parasites, and whatever else that spends it's time bothering fish.

My fish have been through a lot and, it would be safe to assume that they are perhaps not as fit as they could be. In fact its probably safe to assume that they have suffered some gill damage as a result of the poison shrub they were probably exposed to. Perhaps as a result, they are showing signs of what might be a dose of ich.



Signs of ich include fish rubbing on things, presumably trying to itch themselves, and small white growths on their skin.

Ich are up to 1mm in size, and burrow into fish skin and gills, where they live on bits of fish and blood. Once fully grown, the adult ich beastie (tomont) falls to the bottom of the tank or comes to rest on something where it builds a crusty roof over its head and spends a day or so dividing into around 2000 other smaller beasties called tomites. When they get bored and leave their crusty home they are called theronts. Theronts are elongated, can swim, and have a gland that aids in burrowing into a fish where the whole shebang starts all over again. If you're a fish, nature sure is irritating.

When the fish gets one of these beasties under their skin they do what most animals do with this kind of thing. They basically try to build a pearl around it in the form of some gristle like crunchy stuff. I'm guessing calcium and some other stuff. It doesn't matter.  This fishmeat capsule makes it difficult for us to kill off the beasty, so we get it when it's doing the dropping to the bottom, and swimming around stages, when it becomes vulnerable to various chemical treatments.

If your fish are in an aquarium this means buying something from an aquarium shop or vet.

These treatments are unsuitable for fish destined for the table, so in aquaponics we treat ich with salt.

The addition of iodine-free, and anti-caking agent free pure cooking salt is used. Treatment should be at 3 parts pure salt per thousand parts water. That is a scary amount of salt to be adding to a fresh water fish tank, and takes a certain amount of courage to actually do the final adding it to the water bit.


One other way to stop the ich cycle is to deprive them of their fish hosts for 3 or 4 days. ie a fish tank left without fish for a few days will be rid of them.

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 - Fish disease diagnostic tool

This fish disease diagnostic website might be useful to anyone raising fish.

http://www.fishyportal.com/diag/

Tick boxes describing symptoms, then get a short list of possible diseases, and what you can do about it.

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]