Backyard Aquaponics
A place to discuss aquaponics

Hello everyone. I've finally got the time to build I small system, mainly built from scrap or recycled materials. Fish tank/filters and dwc made from an old walk in freezer , greenhouse top made from old pc tubing and polythene. Few old water bottles for filters, 1 swirl filter, 1 small partical filter and 1 bio filter. Fish tank has goldfish at the moment, but will stock with tilapia as soon as i can find a supplier. No doubt I will have many questions to ask as I'm just starting.
And question number 1 .. Where is the best place to test with all master test kit? Ammonia in fishtank, nitrates in bio filter? Or just test in 1 place ? Thanks

Hi cragster, I test for everything in one place with samples from my pond (fish tank). I can see why you wondered though. I suppose you could in theory also compare nitrate samples immediately before and after the grow bed to get an idea of how much nitrate is being used by the plants. Make sure your system is well cycled before adding too many more fish. Otherwise well done let's see how you get on.....

I think you have the idea, depends on what you're goal is when you test. I'll usually test what's going back to the fish tank because I'm more concerned about ammonia and nitrite toxicity and it's effect on the fish, than how much nitrate is available to the plants. For me that testing happens in the sump. It's not that critical in most cases.

Thanks for the input guys. I know through reading all systems differ . Here's what I've done. I filled the FT and GB up and let it sit to degass for 1 week. Ran the system for 1 more week to fix leaks and solve some problems. Added 4 gold fish and a test raft of lettuce seeds. I test for PH it's at 7, but no ammonia and no nitrates and no nitrates hence the question where to test. I know the FT late for only 4 fish. But will wait another week to see before adding more fish

Maybe someone will correct me if I'm wrong here but.... Cycling the system takes time, don't be impatient. Sometimes it can be speeded up by adding small amounts of ammonia into the system and that kick starts the bio filter. This adding ammonia (too much ammonia) is followed by a spike in nitrites (too much nitrites) this is then followed by a reduction of nitrites and production of nitrates.

HOWEVER... you already have fish in your system SO adding more ammonia is a bad idea. Let the fish do it naturally. But don't add any more fish until you are sure the cycling has started.

Adding too many fish before the system has got going will see a spike in ammonia and if the bacteria to convert that ammonia to nitrites then nitrates are not present in sufficient numbers then you could see fish deaths. Your system looks like it holds enough water for quite a lot of goldfish so I'm sure with a little patience you'll be well on the way.....

> don't add any more fish until you are sure the cycling has started.

should read...

cycling is **completely finished** and bacteria is able to handle the load of additional/lots of fish.

> Adding too many fish before the system has got going will see...

stressed and dead fish....

4 gold fish is an OK place to be for a month or so - they are small so things will go slowly.
Don't be surprised if you don't see anything happen in your test kit.
You could add a few more little ones but dont add anything like TIlapia etc at this early stage.
Don't go over board when you do add fish. Avoid buying large lots of 30, 50 etc.

Hi Cragster and Dif..... Just to clarify and so as not to be confused by my description of the cycling as 'started' compared to 'completely finished' it is in fact exactly the same point in time but depends from which angle you look at it.

Ammonia needs to be changed to Nitrites which then need to be changed to Nitrates. Once that's done you could either say 'it's completely finished' which is correct or because it never stops changing Ammonia to Nitrites to Nitrates then I described as 'started' Either way let the amount build up to levels that will accommodate the adding of more fish, if not Difs description of 'stressed and dead fish ' will be far more accurate than mine......

Cheers for the input. I will hold off before putting in more fish. Goldfish are fine at the moment. And I think it will be a little slow as it's winter here and my water temp is around 14C . gives me time to build a solar heater to warm the water up. As the sun is hot in the day . The system drops 1 degree at night and heats up in the day. The test I did with a solar hot water recirculating heat exchanger heated a 55 gal up to 30C in 3 hours. So I'm building a smaller one to slowly bring the temp up to mid to low 20s

Solar heater made .. 4 days from 14c to 19c I hope things might start to happen

Well guys I'm stuck and need advice . System has been up and running for 4 months now. And still nothing . I added 4 more fish as they where given to me. Ph is between 7 and 7.2. Ammonia 0.25 to 0.50 nitrites 0 nitrates 0 . Testing with api master kit. Just tested with the strips from api just in case the master kit was faulty. And the same results . My plant growth is ok. Only basil and a few tomatoe plants in there. Ammonia has been at these levels for a month. I'm really stuck for ideas. Any help would be appreciated
Thanks
Craig

most likely inadequate biofilter.... the conversion of ammonia to nitrates is not efficient.
you probably need at least 200-400L of wet media/bio-objects for a 1000L tank - more if you overstock your fish.

getting 0 for nitrites is OK - probably means that what is being produced is being converted. And in a low producing system you can have nitrates = 0 if the plants are using it. (must be case if plants are growing)

Looking at your posts it seems you lack enough media or bio-surfaces in the system.


You are just running from the tank through the drum filters to the DWC ?

one option is to fill a drum full of rock media or bottle caps etc to give the bacterial a better location to host.
(IMO small rocks would be best as long as they are intert, not limestone etc).
The other option would be to add a media grow bed into the system - you can use some large tubs and put these before the DWC.

i would have to agree with lack of bio filter. something i saw in a fish wholesaler was that they put a single layer of about 1 inch rocks on the bottom of their tanks but loose enough that junk would still flush through when they did water changes. I think that if a person wanted to add some every ease bio filter one could put a single layer of lava rock in the bottom of a DWC bed and increase the amount of bio filtration real easy. as long a there is enough mechanical filtration before the water goes into the bed it should take a while to get dirty. Or one could add a gravel grow bed to.