Cycling the System

[Jeremy Day]

So far the system has been cycling for nearly 2 weeks.  At the start the pH was 8.2 which is what my tap water pH is. The ammonia levels were minimal and the nitrate/nitrite of course wasn't happening.  Here it is 2 weeks later and I have a few plants in there mainly chives, basil, oregano, and some green onion.  The pH is still 8.2 and the surprising thing is the ammonia level is 4-8ppm.  Not nitrate or nitrite levels have been detected.  I have to take this system down on thursday and pack it up for a demonstration so I haven't used Maxicrop yet as it would have been pointless to do so.  After testing the water to see the pH and ammonia so high, I have tried out Miracle Grow Sea to see if I could propagate bacteria that way.  After 8 tablespoons into the 50gal system, the pH is still 8.2 and the ammonia is still 4-8ppm.

 

I have attached a photo showing just 15 minutes ago the ammonia from tap water on the left and system water on the right.  The pH I forgot to get a photo of but in both vials the color in the high concentration was a lighter brown purple.

[Jeremy Day]

After reviewing the photo, I need to either stop laying on my side while using the computer or rotate the photo so the other 99.8% of the forum users can view the image without looking silly at their monitor.  Btw, the water in the flood tank and the fish tank both have a lake water smell to them.  I am an avid flyfisher and that scent something I know too well.  i am unsure what the water should smell like in these systems but that is my take on the water and perhaps that helps someone figure out something in regards to advice on this matter.

[Sylvia Bernstein]

Jeremy, I haven't been following what you are doing, so forgive my ignorant questions but 1) are you cycling with fish? 2) have you done anything to adjust your pH? Have you added any external source of bacteria? What is the temperature of your water?

Where you are in the cycling process right now could be very normal depending on the answers to these questions...

[Jeremy Day]

I am in the cycling process, however, I forgot one of the most important things... its still Spring here and the water temps are ranging from 47degree F to 60degree F.  I think I read somewhere that the bacteria stops when the temp of the water runs below a certain range.  I not added any source of bacteria.  i have put a few plants that were volunteer such as chives and green onion that came up in my herb garden.  I have logged a few days ago the morning water temp was 45degree F and the evening was 67degree F.  After this weekend I will have the system back with all new 3/4 washed river rock and all new water to start over with.  I will load my maxicrop and begin from there.  This time, making sure I have a few heaters to avoid getting the temps too far below.  Since this is a barrelponics with the flood tank, won't the water loose quite a bit of heat going from the fish tank to the flood tank?  I may have to rethink the design of this and not use the flood tank but rather go with the bottom fish tank, the pair of half barrel grow beds and just use bell siphons on them.  At least by theory the warmer water would make it to the grow beds fast and not lose as much heat being in the flood tank for so long.

[TCLynx]

But do you have fish in the tank?!?!

 

As to still having a high ammonia level after only 2 weeks while it is still cool there, (if you are fishless cycling) that would not be a big deal.

 

Maxicrop doesn't provide bacteria though, maxicrop provides potassium and trace nutrients for the plants.  I also don't really recommend using miracle grow in an aquaponics system.

 

An ammonia source is needed for cycling (this can be from fish or from adding ammonia or something that will break down into ammonia.)  Don't add ammonia if you have fish in the system since they will take care of the ammonia for you.

 

Bacteria.  Many people try to add bacteria to their systems in order to speed the cycling but the bacteria will colonize naturally given some time and the right conditions.  In general it takes around 6 weeks to cycle if you add some sort of bottled bacteria and most of the time it takes about half a dozen weeks to cycle if you don't add any special bacteria starter.

 

Just make sure your water isn't chlorinated when you start back up and be patient.

 

As to temperature, simply flooding and draining the gravel beds will tend to bring the water closer to the air temperature.  The flush tank might add to this a little but the flood and drain gravel is pretty effective as a heat exchanger too.

 

[Tom Barnhardt]

TCLynx, do you recommend fishless cycling or starting off with fish? Thanks !!

TCLynx said:

But do you have fish in the tank?!?!

 

As to still having a high ammonia level after only 2 weeks while it is still cool there, (if you are fishless cycling) that would not be a big deal.

 

Maxicrop doesn't provide bacteria though, maxicrop provides potassium and trace nutrients for the plants.  I also don't really recommend using miracle grow in an aquaponics system.

 

An ammonia source is needed for cycling (this can be from fish or from adding ammonia or something that will break down into ammonia.)  Don't add ammonia if you have fish in the system since they will take care of the ammonia for you.

 

Bacteria.  Many people try to add bacteria to their systems in order to speed the cycling but the bacteria will colonize naturally given some time and the right conditions.  In general it takes around 6 weeks to cycle if you add some sort of bottled bacteria and most of the time it takes about half a dozen weeks to cycle if you don't add any special bacteria starter.

 

Just make sure your water isn't chlorinated when you start back up and be patient.

 

As to temperature, simply flooding and draining the gravel beds will tend to bring the water closer to the air temperature.  The flush tank might add to this a little but the flood and drain gravel is pretty effective as a heat exchanger too.

 

[TCLynx]

I like fishless cycling, so much less stress for you and the fish.

[Johann]

I am into cycling for 16 days now with a 10 gallon fish tank that will be put in line at a later time.

I started with 24 minnows with an outside filter and a filter on the suction side and a temperature of 70F.

My test is exactly the same on ammonia than yours with a little bit of nitrate.

You may have to use a buffer to get the PH down. Some companies make stuff to get the PH down, but if it does not contain a buffer it will not stay down for long. Some plants may benefit from some citric acid which may also bring the PH down.

[TCLynx]

Buffers generally only help keep the pH up (like shells.)  I don't know of any buffers that work the opposite way.  Citric acid is not recommended for adjusting pH when you are trying to cycle since it is antibacterial and will hinder the process.