Backyard Aquaponics
A place to discuss aquaponics

Nice update bunson

I'm surprised they are still going!

Keep us updated!

So... I put the mockers on myself by posting yesterday!

I generally only check the pH of my system once a week or longer as it usually sits at 6.7-6.9 without any interference from me. As I said in a previous post, I have been overwintering my barra in an outdoor tank without heating by using bore water to top-up the heat. The ground water here is normally around pH 6.5-6.7 so I've not been too concerned about the amount of ground water going into the system adversely affecting my normal pH balance too much.

This morning I found a dead fish with an ulcer or open sore on its head and one on its body; my initial diagnosis was red spot. I removed the fish and closely inspected the remaining eleven fish. Sure enough there are a 5 other fish with signs and/or small lesions. I haven't had a close inspection of my fish for a while, so I don't know how long the fish have been this way. I dumped most of the water from the FT and salted the remainder to 10-12ppt. They have been in there now for about two hours, and I will leave them for another six hours or so before topping up again. Imagine my surprise when I did my weekly pH test of the water in the system, 5.8! I tested the pH of the ground water, 5.7! I am guessing that recent rainfall has had an adverse effect on the ground water acidity as fertilisers and other crap get washed into the water table, and the height of the water table changes, wetting previously dry levels etc.



Red spot is a ulcerative disease caused by pathogenic fungus to which barra are susceptible. In cold conditions, the fish's immune system reduces and are therefore more susceptible to illness; sort of like how we humans are more susceptible to cold and flu in winter. Less than perfect (acidic) water conditions don't assist their recuperation either. I suppose the ulcers could be caused by a parasite? Anyway, I'm hoping that a few hours in "hospital" will alleviate the problem, whatever its cause. (I'm also hoping the plants don't mind a few hours of some extra salt too.)

Some time ago, I lost some fish to acidic ground water but it was long enough ago that I had forgotten about it. Somewhat rudely, I've been reminded to regularly check the pH of the top up ground water, especially immediately after heavy rain and for a few weeks thereafter.

Sorry to hear about your barra, hope it all works out

What's the latest Bunson?

Hey Charlie...

Seems the worst of winter is over? If not the storms, the cold nights. I ended up losing 3 of the 5 previously infected fish, but with a few more salt treatments (10-15ppt for 12 hours) and maintaining 6+ppt otherwise the last two afflicted fish seem to be ok (blemished, but alive!) The other 11 are still going strong. All 13 fish are feeding strongly already, the water temp is nominally 22+ and I only have to add "warm" water on the coldest nights then top up the salt.

As part of another small experiment I tried using a 300W aquarium heater... Which worked to prevent the temperature from plummeting, but at a $$$ cost.

I'm still going through the UK Visa issues, the last of the paperwork was submitted on Friday,a so here's hoping for a positive result soon? So what was the purpose of the experiment? Is it possible to over winter barra in Perth in an unseated outdoor system... Yes you can, but it takes effort. Would I do it next time? Nope, I prefer trout to barra (to grow and to eat) but I've proved to myself that I can do it, and learnt a bit more about husbandry too. If I were to try it again, I'd be looking at employing better insulation and better methods to capture the available heat; SWMBO would never let me excavate here, but the use of buried components would also help.

I've got some ideas to over-summer trout, but again without excavating, it could be a major challenge!

As an addendum... Groundwater pH here is highly variable, 5.2 to 8.6, day to day and week to week, and requires close monitoring.

It appears the last of winter is behind us? Without topping up with warm water overnight, the FT temperature in the mornings is remaining above 21C and is getting as high as 28C during the day. (We've got a forecast 32C on Saturday too, so will certainly get higher still).

Recent storms decimated (almost) everything that was left in the GB, so I ripped everything out and started with an essentially blank canvas; got some lettuces, a new (for me) variety of cherry tomatoes, kale and strawberries in for summer.

I think I've discovered the issue with the groundwater -- the pH was not fluctuating wildly, the sensor in my electronic meter was dying! I'd hate to think what I was actually doing to the pH as I'd correct the pH of the top up water as it was being (mis)reported by the meter! I've gone back to the API test kit for now (cannot afford another sensor at the moment).

My last real close look at the remaining barra was after replanting the GB about a week ago. Yesterday afternoon I noticed one fish was acting abnormally, I had to go out in the evening but I had a quick check again later to see if the fish was still acting oddly; floating is odd! I took the fish out of the FT at the time, but didn't do the necropsy until I got home later, as it was after dark I did the work in the kitchen.

The initial observation about this fish was that it was silver in colour when all the other barra are much darker; in fact much of this fish was white more than silver and the pigmentation was patchy. There were a number of red areas, blotches and blemishes. I didn't really need to do too much more to know what this fish died from, but I kept going anyway. There were a couple of ulcers/sores/wounds (but different to what was suffered in the system earlier in the winter). One of the sores leaked pus when pressure was applied. Of all the things to find was a chunk of (something) embedded into the head of the fish; the chuck was about the size of a grain of medium-grain rice, hard as bone and denser than water (it sank in water). I've no idea what it was? Having completed the external observation, it was time for the internals; as soon as I cut near the anus with the knife, there was a sudden gush of red-brown liquid from the internal cavity and it STANK! (Good thing SWMBO is not here else I would have been in serious trouble!) I certainly didn't need to do any more cutting to confirm my initial suspicions on the cause of death; I buried the fish in the garden and spent the rest of the night cleaning the kitchen trying to eliminate the stench! Septicemia.

But what caused the wounds? I have a suspicion the deceased fish may have been targeted by the other fish? I'm pretty certain that the wounds were not caused by the same parasites I had in the system earlier in winter, so I reckon the salting routine was effective.

As I've planted some lettuce and strawberries, I've pulled the salinity back to about 1ppt, but I might have to increase this to about 3ppt again? For the mean time, I'll leave things as they are for a few days and see what the hot weather on Saturday does for the system.

Over-wintering barra in Perth, sans-heaters has been an interesting experience and I've learned a lot, but next winter, I'm going back to trout. (I wonder what it's like to over-summer in trout in Perth, sans-cooling? )

Any Barra in this summer, Bunson?

No, Charlie.

The system has been "surviving" on Charlie Carp since I re-activated after coming back from the UK earlier in the year; actually, it's thriving and I'm getting really good vege yields without having to worry about fish. A small bottle of CC is cheap and lasts for ages; if a pump stops, when you've got no fish, who cares!

We're going away again for a short holiday in a little while, so getting more fish just seems like an imposition on the house-sitters... I was thinking of getting some silvers, but they're just too expensive for me at the moment. I think I'll keep the system running sans-fish until next winter and put in trout (my preferred eating fish anyway)

Hope all is well with you and yours. Thanks for checking up on me.

Good to see your still around mate, not many of the older team still here. Fishless seems like the perfect solution for your situation, and considering your getting good yields well thats a win-win.

All is well with me and the family mate. We'll have to catch up for a nice brew some day.

cheers

I was chatting with Sue at Cheidy's today and promised her some photos of my tomatoes...

How I prune them...

Make sure to get the variety which required staking/trussing.






Sorry about the focus!





Hope this helps.

Bunson!!!!!! Where are you