Backyard Aquaponics
A place to discuss aquaponics

Just curious if anyone has used this method and what their experience was?

Many people have and if you search fishless cycling you will probably find many threads about it. Then there is the hummonia version or Pee Ponics if you don't want to pay for pure ammonia or have trouble finding stuff without detergents, soaps, fragrances or other additives that would kill fish.

Fishless cycling is highly recommended by many of us as it takes much of the stress out of cycling for both fish and humans. You can often cycle quicker fishlessly since you don't have to do water changes unless you grossly overdose on the ammonia (too much ammonia will hinder the process.) Once well cycled, fish can be added and water quality monitored while slowly bringing up feed rates to the desired level.

I've fishless cycled using hummonia and it only took 3 weeks during cool weather.

So you just add pee to the fish tank? Also what about using minnows from a local bait shop? I can get 4 dozen for 8$ or so.. Not sure if having something like that would get me anything..

You can do just about anything you want. I don't know if there might be any danger of introducing fish diseases to your system by using bait to cycle and I don't know what you would feed the minnows. Do you like to fish? If you do then it might be worth keeping a stock of minnows.

Some people add pee fresh to the system, be ware it doesn't take much and it can take several days before the ammonia actually shows up on the readings so it is easy to overdose which will slow the whole process.
Otherwise to use pee to cycle. I personally usually leave it in a bottle for a couple weeks to kill off most of the pathogens that might normally be found in a healthy person's urine. (ya don't want to be using urine from some one with strep or typhus or something like that.) Leaving the urine bottled for a period of time does a couple things. First it allows the urea content of the urine to convert to ammonia. Second it give the ammonia some time to kill the pathogens like e. coli that often get into urine. Only drawback to saving it that way is when you go to add it to the system, it stinks worse. Benefit to doing it this way, the urea has already converted to ammonia so you will more quickly get an ammonia reading thus reducing your risk of overdosing the system.

For fishless cycling you want to bring the ammonia level up between 1 and 2 ppm and then let it run until you see the ammonia level dropping and the nitrite level rising. Keep testing regularly. Once you see the nitrite level start dropping you can probably dose again. At some point you should see the nitrate level start to come up unless you already have so many plants in that they suck it right up. Once you can dose the system up to 1-2 ppm of ammonia and have both the ammonia and nitrite readings at 0 ppm within 24 hours, then you can call the system cycled. Keep dosing with small amounts to keep the bacteria and plants alive until a few days before you get fish. You can also use this method of dosing the system when you are between batches of fish or if you just want to run a fishless system.
Reminder, it does not take much pee to cycle a small system. A standard barrel ponics system only required 100-200 ml of pee every few-several days to cycle and 100-200 ml of urine every 2 days can keep the nitrates quite high in such a system when fully cycled. I would say a 500 gallon 1:1 system could cycle just fine on something close to one pee per day.
Granted, these numbers will vary depending on the actual conditions and daily testing is a good idea through cycling so that you actually know it happened. A pH of between 7 and 8 (a little higher is fine too) is good to start cycling, pH is likely to drop drastically as cycling completes, be prepared to buffer the system (oyster shell type chicken grit is a good buffer but it won't bring the pH back up quickly-and changing pH quickly is a very bad thing to do- so add it before the pH drops too low.) Most people call 7 about the perfect pH for Aquaponics, most plants like it lower and most fish like it higher but the bacteria that do the nitrogen cycle will quit working if the pH drops much below 6.5. My system pH hangs right around 7.5-7.6 now days, some plants are not so happy about it but most do just fine.

I do like to fish. Minnows we have down here will eat algae and regular goldfish food. I'm just not sure if they would produce enough "stuff" to get the system going in a timely manner. They are sort of fragile because they are so small so a number of them would die of stress right off the bat but I bet quite a few could survive even in not so good water conditions.

Might be more work than its worth though

If you want to cycle fast do it fishless cycling then you can add your minnows to at least keep the bio-filter active to some extent though remember that a small fish load does not keep the bio-filter fully ready to suddenly accept a huge fish load without any spikes or need to monitor levels and that sort of thing after the sudden change.