Backyard Aquaponics
A place to discuss aquaponics

Can anyone please help
I have a system (small) that has been running well for about 12 weeks or so, everything was fine, then slowly the fish (Goldfish) started to die. I have lost them all. 10 in total in a 80 litres container.
Having tested the water all is good to excellent, except the PH which is very high at or about 8.3

I have cleaned all the tank and debris, but the ph has stayed high over 3 days of checking. Plants are doing ok. What do i need do and what could be effecting it, i dont know
TIA

Oh no dead fish are no fun

Were you testing for ammonia /nitrite during the 12 weeks

Best guess without more info is system was simply overloaded

Has your Ph been high from the start

Is the source of your high Ph your grow media

Unlikely the Ph killed your fish

However high ph causes ammonia to be more toxic , in a small system ammonia can build up quickly

High Ph and high water Temperatures compounds this effect

Chart below shows this effect as you can see at a Ph of 8.3 you don't need much ammonia to be a problem
combined with the Hot weather we have had lately .

If you had a ammonia spike a nitrite spike (toxic to fish) would have followed .

Can you supply more info on your system , photos are a big help

While your Ph is high its best to foliar spray your plants with Iron

If your top up water is high Ph you can adjust it with acid before adding to your system , I think its a lot of mucking around . Much easier to squirt a bit of iron once a week and wait for the natural cycle to bring your Ph down

If you have a nitrate reading (test kit) and no ammonia or nitrite readings your system will be cycled and you can get more fish .

Your fish numbers are reliant on your filtration capacity not your tank size.

+1 - seems most likely

If this was an ammonia spike the first thing to do is to stop feeding to try and keep the levels down.

Thanks for the feedback. Yesterday i did a complete water change as i tested tap water and its ph was ok. End result 24 hours later is PH is still about 8.2 all other readings, I.E. ammonia, nitrate and nitrite are fine.?
I have taken some photos of system as suggested to see if that will solve the mystery.
No levels wer checked BTW once the tank had cycled, so I dont if there was ever an ammonia spike that killed the fish? Could leaching of the timber supports be a problem? The tank was stocked with 10 smallish gold fish , thwre were say 6 slow individual deaths and then 4 all at once.
See attached photos.
Tank is 80 to 100 litres, growbed 40 litres (took one bag of expanded clay pebbles
I have attached the pump im using to return water to grow bed and i have another identicle one to aerate water in tank
Cheers
Can anyone advice how i upload the photos as it sais each file is too big, exceeds 2mb? Must be a way around that

Yes,if the water touches it.It's poison to us too.


You have to resize them.Here's a link; viewtopic.php?f=4&t=107
I think that's it.I can't use this because I don't have windows,but I think it should work.You could use any image resizing programme.

10 gold fish is a bit too much for your system,so if there was an ammonia spike,it will be the likely cause.You need to get the PH under control first.
I read your post on another thread asking about "not adding chemicals" to the water.You need to find out your KH first.If you dump a whole load of acid into the water (hoping it will bring down the PH),you will be destroying the buffering capacity (KH).That method may work for some,but yours is very hard water.You need buffering capacity or carbonate hardness to hold the PH in place so it doesn't swing & cause a PH crash.
And no,your PH won't drop over time because you will be topping up every week with that same water bringing the PH back up/keeping it there at 8.2.You need to add/mix pure water RO,distilled or deionized to your tap water & find the correct ratio that has the desired PH & enough KH to hold that PH in place.
The fish may have been from a bad supplier as well (might be the cause of the deaths),but you still need to get the PH sorted.

So how do you know it had cycled?
Although you would assume all expanded clay is neutral this is not always the case, it ossasionally pops up more so with the cheaper clay.
You could keep a container with your top up water and treat it to bring the pH down as 7341 says but I would use hydrochloric acid to lower the pH. Remember to leave the top up water overnight once treated and retest before topping up.

Well its got me stumped. The PH just seems to be rising? This morning it was 8.3 which is the top of the range on my high PH test kit, so it may be higher? The other levels are all in the excellent to good range. Nitrite and nitrate, just a tad higher than two days ago. the plants seem to be deficient in something, probably iron? Anyway I realise that in such a small system minor changes can effect readings quicker than in a large system. So we have decided to get an IBC and do the cut and chop and run the larger system.
If anyone in the Geelong area knows of any for sale I would be interested. None the less I am curious to know what is going on none the less and how long will the system go without fish?
I think I have managed to add two pics of the plants in this post? But im running Linux and finding it hard to resie. I really want to post the setup pic I have, But basically it is just a 100 litre plastic tub from Bunnings as a tank with a 60 litre growbed diagonally across the top of it. Pump in tank so water rises and falls with the siphon. I have another small pump aerating the water at the surface.

Cheers
Rod

the setup pics resized at last

OK. I may well have figured out the reason for the rising PH levels. If you look closely at aqua_c1.jpg and aqua_g13.jpg you will see that the tomatoe plants are staked with timber (treated pine) it is my belief that this is not what killed the fish, it was probably a ammonia spike for whatever reason, but it is the reason for the upper level PH levels. Could I be right? An thoughts would be good

probably not but it is not a good idea to have pine (treated or otherwise) in the system water.
With a larger system look to having a frame of some sort that you can string the plants up to.

problem with small systems is the pH can move pretty quickly.
Less likely to be an issue in a larger system.

treated pine and other products are not good for the fish anyway.
Similar for care when using galvanised products and water from zincalume roofs.

>> But im running Linux and finding it hard to resize

simply display on screen at appropriate size and screen grab, that is pretty simple.
Google "gimp screen grab image"
You can also use the PrintScreen button on your keyboard (sometimes shift-printscreen).
then just paste from clipboard and crop.


Otherwise GIMP or something should do it directly.
Just googled "GIMP resize image" and the instructions come straight up how to do it, below

With GIMP open, go to File > Open and select an image.
Go to Image > Scale Image.
A Scale Image dialog box will appear like the one pictured below.
Enter new Image Size and Resolution values. ...
Select Interpolation method. ...
Click OK to accept the changes.

Hi guys, new to aquaponics but not to ponds, that 8.3 is a specific ph number. You should test your KH, did you add a bicarbonate to your system. The main reason the ph continues to go up may be due to a high KH. Also yes, pine is toxic to fish. Do not use any treated lumber as well. Remember that Goldfish are a very dirty fish. Goldfish and koi produce very high ammonia levels. If you have ammonia or nitrate is high the fish cannot process oxygen and get whats called Brown Blood disease. Hope this helps!!!