Backyard Aquaponics
A place to discuss aquaponics

Hi Rupert
I was browsing through some topics and came across Gran's where she mentioned that she had fish deaths but with no apparent reason. You indicated that you need the same amount of air volume as tank or water volume. I assume that the air volume you are referring to is L/hour or not?

L/Hour... yep...

And, how about an update Gran?

Thanks Rupert. I think I've figured out what is happening with my barrel system's goldfish.

Here is my update, unfortunately it is not a happy one.
About 2 weeks ago I noticed very very minor growth on the lettuce seedlings I had put in again.
That's it I thought, now it is starting.
Well, 10 days ago three of the smallest SPs gave up within a couple of days, all water levels are fine btw and measured to the manual, very accurate shakings.

Growth is still very very minor but at least nothing is growing backwards and SPs seem to enjoy their food, pellet by pellet by pellet, don't want food not being eaten and contaminating water.

This morning another dead fish, this time a bigger one. Must have happened during the night or even earlier unnoticed. Eyes were not clear anymore and fins are damaged. My guess is the other Sps did that after it's death.

I added a little pool salt (30g) and changed about 80 Ltr of water (500ltr) with seasoned tap water.
Checked levels again and Nitrate was high 40s.

Checked again just now and found 2 more dead fish and Nitrate is 80
Now I have taken away another 100 ltr water and fill up very slowly with tapwater sprayed into growbed.

2 weeks ago I went back to Hydroponics with the towers and the growth rate there is at least 10 times better than in the AP.

Maybe all of that is a sign that my setup in the small, polycarbonate covered little greenhouse is not the ideal situation for an AP system.

I'm very sorry to hear about your fish. It is always tough when fish die and even worse when you don't know why.
What was the pH readings?
I have had silvers die at a pH of less than 6.5, just 1 or 2 a day.

Hi Gran!

Wow, it always feels like you are having a bad run, dont let this get you down because you have our support. Just remember, Rupert has killed thousands of fish so keep that in mind if you ever loose any It helps me get on with things anyways lol.

So first impressions is the open mouths so first instinct is telling me DO issues but its not always easy to tell from pics and a description.

Marc d W
I had 6.4 yesterday.............hm. No more dead fish today though, mind you, it's just 10.15am..........long day ahead .

Charlie
That's a long way for me to go then. I just managed 35 up till now having started at the end of March.
The AP being in the greenhouse (actually more a hot house) lets the water raise to 24 degree at daytime. Come summer the silvers will have to put up with a lot more unless I put up a FT outside.
My FT sitting 2/3 in the ground in the greenhouse doesn't help cooling it. As Faye pointed out a while ago, the growbeds in the greenhouse heat up the water quite fast.
So much to think about and it could well be that the syphons and air pump I've got are not producing enough oxygen allthough fish swim around at the bottom of the tank all the time. That should mean there is enough air in the water, shouldn't it?

There is the next investment on the horizon, Oma needs an airpump. Xmas coming up, no silly pressies or chocolates..........it's an airpump please

Gran if there are no other solutions coming forward I would add hydrated lime in small doses (you can buy 5kg bags from masters) or sodium bicarbonate, calcium bicarbonate until the pH reaches 6.7 or higher and see how they go. It worked for me but my pH was probably a lot lower.

Small being the key word - I add 1/s tbsp at a time to my 1000L system.

Thanks guys for all the advice.
I will monitor and be very careful, only tiny amounts............I got it

The next load of dead SPs will probably be in sight already, the temp in the greenhouse FT was today 29.3 degrees............. one hot day

Hm, managed to get ph level right, plants seem to start growing, all other levels are very good, Nitrate a bit high (around 100) and then Friday evening and Monday morning this:


After investing in AP and "sinking" plenty of money, seedlings and fish I will invest in more thing.
The air pump I have is probably enough for cooler weather to provide Oxygen together with the Venturi/growbed and normal waste from IBC but not for high temperatures so a bigger air pump (600l or more/h) will be bought and if the remaining 2 1/2 SPs don't survive (2 shubunkins seem to be fine) my endeavours into AP will come to an end and I will go back to Hydroponics.
I cut off the strawberry towers from the AP system a while ago and they are slowly recovering in an hydroponics system which produces the little lettuce we use nicely as well.

I have never ever had such a disastrous result with something stretched over such a long time.
I am too old to worry about $#%^& like that every day of the week for months now
I know in the current big scheme of things my worries are minute but why hang on to something that can be easily solved.

Hi Charlie. Looks like I had a similar situation as Gran with my barrel system. I’ve lost all 10 gold fish over a period of a month and most of them I found dead with their mouths open. I’ve double checked and tested the water quality and the Ammonia & Nitrite readings were zero and only got a slight reading on the Nitrate side. I’ve checked all the dead fish’s gills and it was normal. I have a small aerator in the barrel and I was running the pump 24/7.
I’ve noticed that I was losing a lot of water each day, and with 5 almost fully grown jam tomato plants in the GB it might be an overkill for the barrel system’s capacity? Also I’m not too sure how much oxygen plants can use via their roots?
Something started to tell me that my problem is oxygen deprivation plus high water temperatures which are making things only worse. The gold fish that died first were immobile most of the times, staying at the bottom of the tank only a few of them were swimming around etc. and the ones swimming around were actually the ones that stayed alive the longest.

Hi Gran. Sorry to hear about your losses. Like I mentioned in my previous post, it seems like I had a similar situation with my barrel system. I know it is a smaller system but the similarities and frustrations you had with your bigger system is the same I had. I've lost all 10 gold fish I had in the barrel system and I feel bad about it which is not helping my motivation for completing our bigger system. All the best of luck to you.