Backyard Aquaponics
A place to discuss aquaponics

Hello all, I am Oosie from the lovely town of Potchefstroom in South Africa.

I have a new addiction that you are all familiar with, I have started dreaming about Nitrites, Nitrates and a few nightmares about Autosiphons.

A big thank you first off for all of the knowledge shared on this forum. I started off doing some light reading but very quickly got drawn in by the sheer amount of information and tips. I applaud you for sharing the knowledge!

On with my system though.

I bought 3 x 210l motor oil drums, and after cleaning and degreasing them thoroughly (food grade degreaser) I proceeded to cut two in half and modelled the 3rd into my fish tank.

I'm planning on using goldfish as the missus won't allow me to keep any fish that I plan to eat. (Something to do with not eating something that you care for and feed by hand)



The bases for my GB's are 2 old wooden pallets that I refurbished and refinished and sits on top of some concrete bricks. The GB's fit nicely into the pallets and I filled them with 13mm crushed and washed gravel. (Double checked by doing the vinegar test)



My system runs a F&D, pumping water from the FT to the GB's and then using autosiphons to dump directly back into the FT.
I struggled for a while to get the siphons to start and stop reliably, but sorted that out with a fizzy wheat drink in the one hand and about 3 hours of observation on saturday afternoon.



I also have 2 x 110mm PVC pipes set up as a NFT system for Strawberries and Lettuce.



Currently I have some Celery, Beans, Spinach, Tomatoes, Parsley, Onions and Cauliflower in the GB's.

I am cycling fishless at the moment untill the end of the month when I can afford some fish. Using Seagro, a fish emulsion and then some natural hummonia added directly from the source.


Now my question is this, until I have the fish in, how much Urine should I add to my 200l fish tank and how regularly? I know I can test for NH4 and NH3 but the only test available to me currently until more funds become available only tests for Nitrites and Nitrates as well as pH (dipstick kind)

Hi Oosie, welcome to the mad house

Great looking system you've built there, I'm sure your in for a crop of vegies in no time at all. Keep us posted on your progress.

Personally I only added an Amonia source (fish food, bit of pee or a dead goldfish) at the beginning with my systems, I started them in the hotter summer months so they cycled within a month.

How many fish are you thinking of using.

I was thinking of usingbetween 10 and 15 5cm sized Goldfish in the tank. When all the GB's are filled the water in the FT drops to around 90l. This isn't for long as the GB's fill and drain in around 30 mins. Don't want to have too many in there and have them fighting each other for DO when the water level fluctuate.

Although in my aquarium in the house I have about 30 fish in 100l.

Will see how it goes with 15 and then add or remove as required.

.
Does the missus know your planing to pee on the fish? I probably misunderstood but I can totally see how that would work.

She knows...explained the science and she's happy.

Besides, fish swim in their own poo the whole day everyday so a little P won't hurt them.

Woohoo! I got my hands on a clean refurbished IBC and it is going to be added into the system as my FT. Previous tank will become the ST for a CHIFT PIST system.

Cleaned and painted the IBC liner last night, was just so excited!

Planning on using a 40mm SLO to feed the GB's as I have quite a bit of that pipe lying around.

Will post pic's later tonight!

Since my last post I have built the FT and rerouted the plumbing so that I am now running a CHIFT PIST system. But another problem crept up on me.


My Ammonia is off the charts. My test goes from pale yellow at 0.25mg/l to a medium green at 5mg/l, however my test turns out bright blue. Like in Royal blue.

New system that I went a bit overzealous with the hummonia and Seagro(fish emulsion).

I have removed the fish to a containment tank as they were dying and removed all the solids and dead fish. Yet after a week without any added Ammonia the test has become slightly, ever so slightly less bright blue. I also did an initial 60% water change and everyday now a 20% water change. But my ammonia is simply not dropping.

My system currently tests at 7ph and 16'C average water temperature. I even added some rocks in stockings that I got from my local fish shop as well as a 250ml bottle of good bacteria but nothing happened so far.

Am I rushing to expect results already or is there something else driving the ammonia up?

Plants seem fine, but that ammonia!

Cycling time is dependent on temperature.... @16C.... it will probably take 6-8 weeks min...

With ammonia off the charts... you probably wont even begin to cycle for at least another two weeks...

As above... water change.... personally I'd suggest back to 2ppm....

Question.... if you had fish in your system... why on earth did you add hummonia... or fish emulsion... let alone both....

Added the fish after I thought the system was cycled because I could smell the ammonia...

In hindsight that should have raised the alarm.


My tests shows nitrates of 10mg/l and nitrites of 0 so I think the bacteria is there, I just think they are overwhelmed and possibly dying because of the high ammo. pH was 8.2 before I reduced it with a bit of HCl.

So you suggest changing water till the ammo gets back to 2 ppm?

I think the system may be turning for the better and once the ammo gets below 1 I will introduce the fish back into the system. I will also salt to 3ppm.

Question though, our tapwater is treated with chloramine and as I understand it its chlorine and ammonia and that when the chlorine bubbles off you are left with the ammonia in the system. Am I correct in assuming this or am I completely wrong?

Chloramine is a combined chlorine/ammonia bond.. the chlorine will off-gass if exposed to UV in time... but it takes longer than straight chlorine.

Chloramine can actually feed the system due to its amm component, but this is why it is toxic to fish in large quantities and can actually crash a virgin system. Top ups will be ok but if you need to do big water changes during a HSM you can actually compound the issue.

Neutralisers and activated charcoal filters can break the bond to free up the chlorine to aid in faster off-gassing but the amm component needs to be taken into account. Usually when using these options you need to take care as amm reading can return false.

I think it is best to have a barrel or 2 of "off-gassed" water on hand in case of large water changes are needed (+50%) if chloramine is a suspected to be strong a water source.

Relief at last. After the last water change last night, my ammonia readings came down to 1,5mg/l so I am quite relieved.

Planning on introducing the fish slowly in batches of 5 from the inside aquarium every second day until all 25 is in the big tank, hoping this will help stabilize the ammonia and give the bacteria time to keep up.

My system is somewhat cycled because I am detecting nitrates at 10mg/l even with the plants in and nitrites of 0 so all seems well.

Will also add a charcoal filter to help with the breakdown of Chloramine, as well as salt the system to 2mg/l to keep the fish happy after transfer.

Holding thumbs that this will work out well.

Hey Oosie, great system buddy. Not sure how I missed this thread but have now caught up.

Looking forward to seeing the IBC included into the system.

Regards, Martin.

I have the IBC incorporated as a fishtank, but I've been lazy in taking pictures. Will see if I can take some tonight and post them.


Question: Is 30 x 3-5cm goldfish too much for my filtration in a 1000l tank, or should I add more fish?

I look forward to the pics Oosie.

You need to work out the fish weight versus grow bed size. Do a search on this forum for "stocking density" and you will see lots of discussion.

This is one of the comments I've seen:
"Fish should be stocked at 1 fish for every 9.5L to 10L. So you could put 100 fish in a 1000L tank as long as you have the grow beds to support the filtration. Another guideline ratio is to have 20kg of fish per 1000L. A third guideline ratio is to have 5kg of fish for every square meter of GB surface area. When starting a new system it is best to understock to keep the Ammonia under control. A new system cannot handle an Ammonia spike very well as the bacteria in the GB is not yet a mature system."