Added aquaponics ibc tanks to existing pond

[Gaffatron89]

Hi all,

I have had a 3000 litre koi pond in my back yard for about 5 years now, about 4 weeks ago I added 2x aquaponic grow beds above 750 litre ibc tanks which circulate water from the koi pond into the grow beds.

I was experiencing slow plant growth so I added some more fingerlings to the aquaponics (I now have about 55) and the koi pond has about 12 koi and gold fish in there things seem to be speeding up as I have been boosting/supplementing the aquaponics with my own urine.

I have been keeping and eye on the levels and the last few days my ammonia has gone to .5ppm but nitrite and nitrate are 0ppm, do you think adding the extra water, media plants etc has given my system a cycle crash? And it's now starting again or could it be that I didn't have enough beneficial bacteria in my pond and its not yet colonised my aquaponic grow beds?

Any help or theories would be much appreciated !

 

[Gaffatron89]

I will add i do have mechanical filtration!

 

[Lisak1]

Welcome to the GPF!

Is your goal growing things aquaponically? Or is your primary goal healthy fish? Because quite honestly your pond is WAAAAAY too small for that many fish, most especially koi. Even with your two aquaponic systems you are at barely 1000 gallons US. That's big enough for ONE koi.

Sorry to be the bearer of bad news - it's a common theme here on the GPF. And yes, I know - five year old pond, everything has been fine... until suddenly it won't be. You're seeing an ammonia spike - that's the first sign that you may have reached the tipping point. While everything else in your system stays the same, your fish continue to get bigger. Waste production increases exponentially. Increased filtration will help, but there are definitely limits that you simply cannot overcome.

I'd suggest you start re-homing some of the big fish. You'd be fine with goldfish. Oh, and stop peeing in the pond.

We'd love to see photos of your set up by the way!

 

[Gaffatron89]

Hi Lisak1,

I will definitely post some photos tomorrow when its day time!! (from Western Australia)

I have about 3 koi 30cm and the rest are goldfish and 2 koi fingerlings. they seem happy even though the pond might be a little small (roughly 9m x 1.5m x 0.4m)

What has been odd to me is that I have not registered any nitrite or nitrate in my system just the small spike in ammonia? which is possibly coz I have been over feeding and peeing in the pond to register some nitrate as fertiliser for the vegetables im growing?

 

[WaterGardener]

What is your pH and KH?

 

[Gaffatron89]

 

[Gaffatron89]

What is your pH and KH?

Ph is 7.0, I dont have a KH test sorry! Thinking hard water may have killed beneficial bacteria?

 

[WaterGardener]

I was thinking you may have had a pH crash and that the water was acidic, killing the beneficial bacteria. That doesn't seem to be the case right now, but a pH of 7.0 doesn't give you much cushion. The nitrogen cycle constantly produces acid, so there needs to be some buffer, KH (alkalinity), to keep it from dropping into the acidic zone. I use baking soda to keep my KH up.

Hard water won't kill the bacteria.

 

[Gaffatron89]

Could it be the sudden shock to the system (new fingerlings, pee and volume of water) and that the quantity of bacteria hasn't caught up? Am I correct in saying that the amount of bacteria in the pond is subject to load on the system/pond??

 

[WaterGardener]

If there is an established bacterial colony, it will catch up very quickly if there is sufficient surface for it to grow on. Under ideal conditions, temperature, food supply, pH, etc., it can double in 20 minutes. You don't want to keep overwhelming it, as it seems to be at this point. Stop peeing in the water and see how long it takes to catch up. It may be that you need to add more filtration, or at least more media for the necessary additional bacteria to grow on.

 

[Gaffatron89]

If there is an established bacterial colony, it will catch up very quickly if there is sufficient surface for it to grow on. Under ideal conditions, temperature, food supply, pH, etc., it can double in 20 minutes. You don't want to keep overwhelming it, as it seems to be at this point. Stop peeing in the water and see how long it takes to catch up. It may be that you need to add more filtration, or at least more media for the necessary additional bacteria to grow on.

Thanks for your time in replying, I will definitely stop peeing it and keep track. If the pee is throwing it over the ammonia should clear in a day or 2? And can I please ask your thoughts on why I am getting zero nitrite and nitrate??

 

[WaterGardener]

How long it will take the bacteria to catch up depends on those factors I mentioned before. That many fish will provide more than enough ammonia for the bacteria to live on and grow, if it has sufficient places to do that and the proper environment.

You could have had a pH crash at some point, killing the beneficial bacteria. So your pond is no longer cycled. It looks to me as though it needs to go through that process again to get established. That's my guess.

Or it may be that by peeing in the water you are constantly adding more and more ammonia and the system doesn't have a chance to catch up. Maybe it will be able to stabilize itself if you just let it be.

If I were you, I would get some Prime or Safe, both made by Seachem, one a liquid and the other a powder. It will bind the ammonia and keep it from harming the fish. It will last only 48 hours for that purpose, so it needs to be done regularly until the pond is cycled. Water changes will also help keep those number down. I would also test for KH and boost that if and when needed.

I'm certainly no expert, so that's Just my two cents worth.

 

[Gaffatron89]

I

How long it will take the bacteria to catch up depends on those factors I mentioned before. That many fish will provide more than enough ammonia for the bacteria to live on and grow, if it has sufficient places to do that and the proper environment.

You could have had a pH crash at some point, killing the beneficial bacteria. So your pond is no longer cycled. It looks to me as though it needs to go through that process again to get established. That's my guess.

Or it may be that by peeing in the water you are constantly adding more and more ammonia and the system doesn't have a chance to catch up. Maybe it will be able to stabilize itself if you just let it be.

If I were you, I would get some Prime or Safe, both made by Seachem, one a liquid and the other a powder. It will bind the ammonia and keep it from harming the fish. It will last only 48 hours for that purpose, so it needs to be done regularly until the pond is cycled. Water changes will also help keep those number down. I would also test for KH and boost that if and when needed.

I'm certainly no expert, so that's Just my two cents worth.

Will definitely look into the products you mentioned. Thanks again for your time i really appreciate it!

 

[WaterGardener]

You are very welcome. I hope your pond is sorted out soon and that your fish and plants thrive.

Best of luck.

 

[j.w]

@Gaffatron89