Backyard Aquaponics
A place to discuss aquaponics

ok, so since I killed 50 Jades at the start of Feb by overstocking a 700 litre FT in which the ph was 8, I have been preparing for the next batch of fish. I have a simple single IBC setup (1 GB on top of 1 FT, no sump).

I've been fishless cycling with doses of fish emulsion, spiking ammonia to 1 then monitoring the drop in ammonia and spike then drop in nitrite. It is taking 24hrs to go from ammonia 1 to 0.5 at which time nitrite has risen from 0 to >2, another 24hrs for ammonia to reach 0 and nitrite to drop below 2, and another 24hrs for nitrite to hit 0. So I'm satisfied that nitrification is working. Plants are growing nicely.

I have also been trying to get ph down as well. I read a number of posts on water chemistry and have been taking daily ph readings and adding 1ml 32% HCI (hydrochloric acid) after each reading. The ph has stayed pretty steady in the 8-8.1 range depending on time of day with the water temp staying in 21-24C range. Since early March I've added 40ml HCI so my tap water must have a lot of buffering to use up. There are no components of the system which could be adding buffering (from everything I've read) so I am assuming it's all the buffering that was in the tap water.

My plan is to:
1. Order some more fish - maybe 20 jades or silvers - to go into the FT in the next week or so.
2. Keep adding HCI in 1ml doses to try to get my ph down just a bit.

So my question is, does anyone think I'm on the wrong track? All thoughts are welcome. Thanks.

maybe try 8 fish in a single ibc setup
and the best way to bring ph down is to let it come down naturally it will if you let it

Hi Tallman,

Yea I wouldnt be too fussed with your high PH just yet as it normally comes down in time as the system matures. I would just treat your top up water for the moment. You will find that if you are constantly adjusting it down it will just swing back up again and this is what does more harm to the fish so patience is your best friend for the moment.

Ok, so the consensus seems to be that I should stop the HCI injections.
Although from what I've read, the fact that my 700 litres of water has absorbed 40ml of HCI with no change in ph makes me think my water had a huge amount of buffering, and might have taken a long time to chew through that buffering naturally (via nitrification). I am a complete novice in AP and water chemistry so that is not meant as a rebuttal to the advice you guys have given - it's just the impression I have from reading. I promise to think about stopping the HCI and trying to display some patience. Ho hum.

And I'll also take the advice re stocking level and go lower than I planned. One complicating factor though is that so few suppliers will sell such a small number of fingerlings. I was looking at SEQ Fish and their min order is 25. I'll look at others but if anyone knows a SEQ supplier that will do <25 I'm all ears.

Thanks again guys.

Hi again guys.
So I have done as I said I would and stopped adding HCI, and I'm working on my patience. That can't be a bad thing anyway.
Have continued cycling with Charlie Carp and that's going well.
PH is still around 8. Sometimes 7.9 first thing in the AM and always 8 in the late PM. As you've advised me, that will drop as the system matures.
I've got 700L FT and the GB is about 230 L actual water volume. It's been running for a bit over 3.5 months now.
So I was thinking of putting in 10 fingerlings, which is a lot less than the minimum order from the suppliers. Well, technically that's not true - they are happy to sell me 10 at the min order price of $50. Hmm. I understand: uncommercial order sizes are just a hassle for any business.
Can anyone who lives in Brissy help me out with obtaining 10 fish? Anyone want to split an order (of say, silver or jade perch)? Or anyone a little overstocked and want to sell a few?
Cheers all.

Alright! Thanks Wildfire for the fish.
I now have 10 little (well, 250g-ish) Jades in the FT.
Sweet!

Hi Tallman, I'm watching your thread with interest as I have recently managed to kill my fish by overstocking an IBC (refer to viewtopic.php?f=29&t=11855 ).

I have recently redone my system and it is now cycling and I'm about to plant it out. I was curious about how you go about spiking your ammonia? Heard about it, but never had to do it. Thanks.

You need to introduce an amm source Matt, charlie carp is a good one. Basically you are replicating a stock of fish and cycle the system before fish introduction....the best way to prepare your system and get a nitrate colony established - or you can seed your system by using some seasoned media from a friends system but you need to keep providing an amm source.

Search fishless cycling for all the info related.

Thanks Charlie, thats an easy one for a change.

Yep, that's exactly what I did (Charlie Carp), after reading posts here on BYAP.
Good luck with the cycling and restocking Matt.