Backyard Aquaponics
A place to discuss aquaponics

Hi, we started our journey into the Aquaponics world about 9 weeks ago and are now at the point where we need some advice specific to our setup. I’ve always been an avid gardener of vegies and herbs but throwing in the aquaponic elements has me a little unsure as to whether or not I’m interpreting the events of this eco-system correctly. Are we reacting the right way to the events? Are there any other factors we need to consider?

Following is our little story so far:

We were lucky enough to be given an IBC for free (thank you Uncle) so followed the IBC of Aquaponics guide to put our little fishy project together.

Thank you to all involved for this guide and for this forum. Whilst it is information overload sometimes for this newbie it is invaluable and greatly appreciated!!

Pump = 3000L bought new and then my Uncle said he has an 8000L pump for us. We will have to save that one for a future project I think

GB = 150 L

FT = 850 L

Sump = we don’t have one

Aerator = only what gravity is providing when the GB empties directly back into the FT

GB medium = clay balls

Water = we started off with Rockingham’s finest tap water - pH 8.4 - filling the FT to the 600L mark.

Standpipe = we don’t have one only the surround is in place. The GB overflows when we put one in place.
Flood and Drain @ 15 minute intervals

FT wrapped in weed matting and shade cloth

To kick off our system we decided on the ‘peeponics’ so hubby made a couple of trips to a bucket which was left outside for a few days before being added to the FT

I transplanted some vegie seedlings from pots to the GB and we left the system running for a few weeks to do its thing. In that time we had enough rain to fill the FT further which reduced the pH to the point where we decided to send in some troops – 4 gold fish.

Water readings:
pH = 7.0
Ammonia = 8
NO2 = 0
NO3 = 0

New growth on plants looking healthy

A trip to home town to visit family resulted in a fishing expedition to the local freshwater river. 3 bream and a grunter were then added to the system.

Water temp – fluctuates between 12 and 16 C
Salt level – unknown
Ammonia off the charts so Ammo Block added
Central leaves on plants looking a little yellow so a capful of Seasol added. This of course made the water darker which in turn made the Bream and Grunter happier.

29/5 Woohoo our first positive reading of Nitrates and we thought we were successfully on our way

But then …

We had to go away suddenly for four days and I had an accident with the feed before we left. I thought I had scooped the majority of it out but I can’t have because when we got back the pH had dropped to at least 6 but I think it was a lot lower as the pH test colour result was a VERY pale yellow, green algae was visible in the GB, there was a film on the surface of the water in the FT and the fish appeared to be labouring for breath.

Water test results:
pH - <6
Ammonia – 8 but don’t trust this as ammo lock added to water
NO2 - 0
NO3 -5

I turned the pump on 100% to continuously flood the system for 24 hours
Changed about 30% of the water out for tap (no other source available)
Added 250g of pool salt (without knowing the current salt levels I erred on the side of caution)
I dragged the net across the bottom of the FT to see if I had missed any feed. I found some pellets, maybe ½ tsp worth
Wrapped the GB in weed mat to block the sun further and topped it up with half a bag of clay balls where the media and plants had settled further and the water was visible on the surface.
Also threw out some plants which had died

Four fish then died over two days (all the Bream and Grunter)

So the pump went back on 100%
Ammo Block was added to the water for the second time in 2 weeks to counteract the high reading which seems to be staying despite the change out of water.

I investigated the GB further to find quite a few plants with rotten roots. Some had new white shoots amongst the rotten ones so I took that as a sign the system was on the mend. I pulled out the plants and threw out any which had the majority of their roots rotten. Washed the good ones in Seasol and replanted them.

But given all that had happened I fully expected to be back to square one with no good bacteria left to work their magic.

Water test results:
pH - <6
Ammonia -
NO2 - 0
NO3 - 5

Only 2 goldfish left – the runt and the big boof of the group. After what they have been through I think it is time to give them some real names Will have to think of something appropriate.

7/6 After a week and a half of levels plateauing we decided to be brave and add some little Silver Perch Fry to the system.

11 SP fry and 2 goldfish swimming happily for a week but then ...

13/6 one SP died. The pump went back on 100% for 2 days solid
250g of pool salt was added
Ammo lock added

14/6 2 more SP died
water temp 14C
pH = 6.4
NO2 = 0
NO3 = 5

16/6 no more dead fish
Water temp 16C during the day
Pulled out most of the plants from the GB because their roots were rotten.
New seedlings added to GB and pump put back on timer

50 L of fresh water from water tank added to top up FT to 700 L level (the water in tank being Rockingham’s finest which had been sitting in a tub outside for a few days)

FT pH = 6.4

17/6
Removed 150L from main FT
Replaced it with 150 L from water tank

18/6
pH = 6.4
Ammonia = Ammo lock in water, +8 reading
NO2 = 0
NO3 = 5

The runt of the SP’s was swimming erratically (nose first) so set up a little aquarium inside with FT water plus salt for him.

21/6
runt SP swimming a lot easier in the little FT (now thought of the hospital tank) and the other fish in the main FT all appear well

Main FT
pH = 6
NO2 = 0
NO3 = 40 - 80

Hospital FT
pH = 7.4 – 7.6
NO2 = 2
NO3 = 20

22/6
75% of water removed from the hospital FT and replaced with water from main FT a teaspoon of pool salt also added to hospital FT

surface pond plants added to both tanks
water temp fluctuating between 10 and 15 C

But then today 23rd June, I noticed a SP staying nose first and gasping near the pump in the main FT. He is now in the hospital tank along with two others. There appears to be a white mold/fungus on their fins I'm not sure if I should put the healthy little runt back into the main FT now or leave him in the hospital FT. He appears to try to eat the mold/fungus off of the three other fish What do you think?

I’ve checked a couple of the others in the main FT and they have no sign of this. They are swimming comfortably at all levels of the tank and their fins all appear to be healthy. But then I only netted a couple as I didn’t want to stress them out too much.

Last time Ammo lock was added to the main FT was the 13th so I’ve dosed the water again and added 250g of salt. Is there anything else that I can do? Does anyone know how long Ammo Lock stays effective in the water?

The other issue we are having is that the fish do not seem to be eating. Almost all of the floating pellets we put in, are scooped out within the hour? We are using 3mm pellets which we have laboriously chopped as we couldn't get any 2mm at the time.

Looking over this it is not such a little or short story after all ☺ Hopefully I haven’t bored you silly but we are looking forward to reading any comments and words of wisdom you have to share.

I will try to reply with some photos of our setup and the sick SP very soon. I just have to work out how to resize the images and insert/attach them to this forum as I've never been involved with a forum before.

Thank you,
Carmel

P.S there is no sign of any green algae in either the GB or FT but there is a brown residue on the FT at the water level.

Silver perch won't eat much or at all when it is this cold, and with ammonia that high I would not be feeding at all.
Why does the GB overflow with the standpipe in? can you cut it down to a level that allows the water to drain?

Hi Gazza
Thanks for your reply. I thought with the cold they would be off their food but not as much as they are
We experimented with many lengths of standpipe but even with a standpipe of only a couple of inches long the GB overflowed within the 15 minutes so we have removed it all together. It is only the surround left in place and the GB drains well without overflowing now.
Cheers

Photos are good

Hi since posting the above we have had a couple more casualties But I've worked out how to resize some photos so here are the latest events, below are some photos of our setup and another post follows with photos of the fish.

I've just completed a 50% water change out in the main FT. Water readings now:
Temp 14C
pH 6.6
Amm 4-8
NO2 2
NO3 5

The fish haven't been fed for almost a week now

In the hospital FT 75% water change. The fish that were struggling to swim in the main FT are now swimming around strongly.
Temp 19C
pH 7.2
Amm 4-8
NO2 2
NO3 5

After weeks of no NO2 levels at all we suddenly have a spike?

Hopefully someone can tell us whether or not we are doing the right things (or not) to try and get our little fishy's back to good health!

Cheers
Carmel

Following are photos of the sick fish ...

Im not sure what kind of ammonia bond you are using but using a chemical to bind, take up, neutralize, or block ammonia, is not only unnecessary and undesired, but it is counterproductive and will be harmful to the stability of your system in the long run. Additionally, using these chemicals can be misleading.

These chemicals will bind the ammonia into a form that is not going to be bothersome to your fish, but also is unavailable to your biological filter. This means that your biological filter will not have the nutrients it needs to stay viable and it will deteriorate. Then, when the chemical has absorbed all the ammonia it can, the ammonia will begin to build up in the system in a form that is dangerous to your fish and will cause ammonia stress. Since your biological filter has been being starved, it is unable to process this waste and your system will begin to cycle again which is what you are seing in your random test reults.

Also, these chemicals often do not bind the ammonia away in a manner that makes the ammonia undetectable by standard ammonia tests, so it will still appear that your tank has a high ammonia level if and when you test the water for ammonia. In addition, some of these chemicals will even read as ammonia themselves on some tests, so you may get a reading for a much higher ammonia level than in is the tank. This can be very misleading and confusing, and it is all because of the use of an unnecessary chemical treatment.

Looking at your fish I think you need to treat them in your main system as a whole to ensure parasites are erradicated from the system. Get yourself a ATC refractometer online (approx $30) so you know what levels of salt you are adding. Do 30% water changes once a week and keep your salinity at 3 or 4ppt. Thats 3 - 4 kg per 1000L of water. Stop feeding and stop adding amm block.

Keep us posted.

Thanks Charlie. You have confirmed what I was beginning to believe and I can move forward with a lot more confidence now.
Advice greatly appreciated!!!
Cheers

Bump.