System Cycling

[mike conley]

I have just finished a small flood and drain set up in my greenhouse and have a couple of questions on cycling. 
A local Aquaponics guy mentioned cycling his using feeder goldfish, which I did. I bought 100 feeder fish, lost about 1/3 out of the gate, another 1/3 over a couple of weeks (all pretty expected) now I have 20-30 goldfish living happily in my 100 gallon tank.for almost a month (I like the little guys so was quite happy they lived!)
My system is a 100 gallon fish tank with a sump below, flooding two 10x2x8" grow beds with bell siphons (boy that was a learning experience!) I used haydite for the grow media.

So, while I was messing around I had a few volunteer tomato plants so I stuck them in about the time I added the fish, just to see what happened, two in one bed one in the other and I threw a few other small plants in the gutters I use as pre grow space before it dumps into my grow beds

Ok, so its been at east three weeks, and everything looks great. filling draining, right level, fish are living (Goldfish) and the plants are thriving! So I get a test kit and test PH, Ammonia, and Nitrates (damn set didn't come with nitrates!) So I have a PH 8 ppm, and no measurable ammonia, and minimal nitrites.I would think, hmm, not done cycling yet, might need to address the PH, but the plants and fish are thriving? 

So, do I leave it be and let it keep cycling, do I add a bit of ammonia to kick start it, do I add some pond water or media from the local guys system, do I go ahead and get my desired fish?

If I had didn't test I would say my system is working excellent and I am ready to go buy some fingerlings, but the tests are throwing me. Advice? 

[Kent Evans]

Mike,

Three weeks is only about half way there, you need to test for nitrates to know for sure. I guess we would all like to think that our system has come on line faster than the norm, but it's just wishful thinking in most cases. You need to see measurable ammonia today and zero ammonia and nitrites tomorrow for 3 to 4 days in a row. before you add the fish you would like to grow. Add a small amount of ammonia if you need to (maybe a teaspoon) to have something to measure, and repeat for several days. 

[mike conley]

So should I remove the couple of plants I have in there or just leave them?

[Harold Sukhbir]

Hi Mike,

Your system is cycled and good to go. You can add fish of your choice and grow more plants.

[mike conley]

I think I am going to add yellow perch 5 at time and see how it goes.

[Jon Parr]

Keep us posted. I second the motion NOT to add ammonia if fish are present, though I wouldn't say you are cycled just because some of the original fish are still alive. Maybe, but maybe not. You're numbers look good, But a few little fish in a big system might be deceptive, especially if they haven't been fed a lot. I've had new sterile systems cycle in as little as a month, but that is ideal for sure. And yes, seasoned media and water will certainly speed cycling. I don't ever have to cycle anymore, just fill a new system from and old, and I'm finished.

Keep your plants in there, and DO plant tomatoes in a new system. Vegging tomatoes just want nitrogen, and will grow fine. By the time they want more nutes to flower and fruit, your system will be seasoned enough. My very first AP was a 55 gal aquarium tied to a 5 gallon bucket of rocks, and a single tomato seed. It ended up sprawling 20' in every direction and pumping tomatoes for almost 3 years.

As long as you also add some chelated iron and magnesium, you'll get decent results at a pH of 7-8. Your pH may come down on it's own, but may not, depending on your source water. I keep mine at 6.0-6.4, and also important to get a KH test kit and keep your carbonates above 40 ppm. Happy growing.

[mike conley]

So I noticed my tomato plant leaves getting some black and dying off. I checked all of my numbers and found that i have lost all of my Nitrates, and am showing no nitrites or ammonia. Not sure why. I also noted my PH had jumped to 9 (was 8 but had dropped to 7 previously.

So I am not sure what the hell that means. the Goldfish are healthy as can be, the plants are doing OK and even getting some blossoms, but I am showing nothing as far ammonia, nitrites or nitrates. I can't figure it out.

I am ordering some perch and bluegill fingerlings and figure I will add them and see what I get, unless someone has some other ideas.