Backyard Aquaponics
A place to discuss aquaponics

It's hard to say what the best course of action is. Probably start by checking to see if any of your media is limestone or if the sand is actually limestone dust or if it is silica sand.

So I have eliminated the sand and gravel as the problem. Put in vinegar and no fizzing. Used cider vinegar. Is that strong enough?

I have also taken the koi tank offline and moved what remained of the koi in the main tank for now. I Think that could of possibly been leeching out alkali from the fiber cement. I was also not sure of the safety of the paint I used on there.

Just trying to revert to a previous time when the pH was not so high.

Trout Time is coming up and I need to solve this pH issue soon!

could a buildup of snail shells be pushing my pH way up?

Shells could push pH up. I don't really know much about snail shells, there seem to be a wide variety of them.

Holy Bloody hell DuiNui! thats the biggest darn fish i have laid eyes on!

Alright. Things are NOT going well! I will be practicing hydro very soon at this rate. Loosing fish daily. Lost one of my biggest fatest tilapia today. Three died when I changed over to the smaller pump as the bigger pump failed. Now the fan has failed too! I am thinking of ditching the tilapia in my brothers pond and cleaning out, remodelling and starting from scratch in the greenhouse.
I think as a result of the high pH fishies are very sensitive to ammonia and any slight spike is just knocking them off. That is just 1 theory. Toxins in the water is another. The frames are rusting but it all goes outside the system I think.

The one dead tilapia had a very swollen gut and when I popped it just masses of yellow runny watery liquid came out and the gut area looked like a popped balloon. Any ideas anyone... anyone... But today's deadie looked very healthy. My one friend who has expierience with Tilapia it aquariums said the Tilapia kill each other. Is that possible?

Tilapia can get very aggressive with each other, especially about breeding. The males can get territorial and can beat up less aggressive males and they can stress out the females chasing them. A Female holding eggs can get really aggressive and kill other fish when she is getting ready to release the fry.

The theory about toxins would make me want to check the system closely since you wouldn't want metals building up in Hydro cause that would be bad for you too.

Test kits required! Thanks Tcl. There was a point when there was a lot of workshop dust. Possibly treated wood. Treated wood. How would I check for heavy metals? In the case of todays death there was no obvious sign of bullying or injury. It looked pretty healthy this one. Could this be just a diet thing? I give them some chard which has that weird toxin in it doesn't it? I have been giving them koi food and a few trout pellets. Could the trout pellets be off. They are pretty old now. What caused the swollen belly thing? So many questions... So many different looking deaths... I know google!

There is now 1 surviving Koi. Swimming around in the big 4000 liter tank all alone.

I hope chard doesn't have any weird toxins, I eat it raw all the time.

I think you need to eat a couple of hundred kg's for it to be dangerous. Anyway it's not that. It's streptococcas. Makkes complete sense from all the symptoms described. Probably came in with the fish or with the mozzie fish or something. I can check pretty much all the boxes in the symptoms list and it is supposedly very common. Probably have that other thing too. Stich or whatever as fish have been seen flashing and rubbing themselves on the slo and stuff.

So I am thinking do a cull of the remaining fish and clean out and sterilize the whole thing and start from scratch. Big system is probably also infected! Aaargh!!!

Can one just bomb the system out with some kind of disinfectant. Perhaps hugely high ammonia? Is it even possible to do this with media in or does it require all media out washed, sterilized and replaced. Time to search the threads...

Maybe you could disinfect the tank and rinse it well, then refill and run UV disinfection on the water as it goes into the fish tank from the growbeds. I wouldn't sterilize the growbeds because you'll loose your filtration bacteria. If your water doesn't have much in the way of particulates that could block the UV light this might be an option.

Yep just make sure the UV sterilizer is sized right for the flow rate.

Things still ticking over nicely although I currently have 1 fish! The last remaining Koi still surviving and very healthy. He is in the big tank. Will need to go for trout very soon! Time is moving on and I am missing valuable grow out time. It is quite amazing how the system is holding out with virtually no nutrients. I have peed in there a few times and the odd splash of worm tea now and again, but the plants keep on growing just fine...

A plant only takes 4% of it's nutrients thro the roots, the rest it grabs from the air, so they will be OK for a while as long as they have water air and sun.

Well, what with the fact that the greenhouse fan bombed out, all the fish had died and the tomatoes had become a bit long in the tooth and quite root bound in places, I decided to take the gap and do some remodeling.

Have decided to ditch the fish tank and use the sump as the fish tank and run CF or try go with the siphons again. This way I can seriously up my growbed volume by a substantial amount from 500 liters to 1100 liters. This should provide more adequate filtration! All I need to do is take down the solid roof at the end of the greenhouse and replace it with clear, shift around the growbeds and weld up some stands for the additional beds.

One thing I have realized with the greenhouse... what with all the fans and control issues and a the hassle factor, it is best to try and maximize the growing area in the available space.

I will also lower all the beds to allow for the higher tomato and cucumber plants which where hitting the roof too soon before.

I can also sterilize everything and kill off all the streptococcus infection and those blasted snails must DIE!!!

Other interesting news... I think I can explain the pH in the greenhouse. Under some of the gravel I found a strange rock which had a very active reaction to vinegar. I can literally see how it is being dissolved away....

So basically quite stoked and looking forward to the changes. I think it is going to be much much better...