interpreting the cycling data

[Allie Wilson]

Hi all,

I am going to start out by saying that I totally get the theory of aquaponics and the ammonia being converted to nitrites by bacteria and then nitrates by another bacteria and the plants taking it up etc etc.  However, I am having a heck-of-a time doing this in real life!  

So I am doing a fishless cycle inside my office and started in early June.  For the last two weeks my ammonia has been down (I still add a tiny bit) but my nitrites shot WAY up.  I started getting measurable nitrates, but then they started to fall.  At first I thought the nitrates were starting to go down because the plants were taking them up, but I am just not sure because they are back up again.  They started going up when I started adding a little bit more ammonia than before (which I think this is a good thing); yet, the nitrites are not falling.  This might be wrong (please explain why if so) but I was under the assumption that when the nitrates were present then they would start to "eat up" all the nitrites and eventually the nitrites would go down.  Here are some pictures of my  Testing done today and the Data I have from the last week or so.

Thanks Everyone.

[George T]

It seems normal to me.  The second bacteria phase is still developing.  The plants are taking up nitrate but the bacteria which convert nitrite to nitrate are not fully populated.  Could you describe your system, amount of water, gravel, fish, etc?

[Allie Wilson]

Thank you for your response George!  I am glad it seems normal to you.  Maybe I am just not patient enough.  Its just I thought the bacterial colonies would be working by now.  It

We have two systems, both are ebb and flow.  One is on a timer and the other is a bell siphon.  Actually the bell siphon is the AquaUrban from Aquaponics Source.  We have not put fish in yet because I wanted the nitrites to go down before I put them in there.  Both systems are 30 gallons.  We use they clay pebbles as media.  Have some cucumbers crawling around, kale sprouting, lettuce, lemon basil, swiss chard.  We had strawberries in there but they all died.  I am thinking there was not enough established nutrients for them?

[George]

Failure to thrive/grow can be expected in a new system but generally not sudden death.  If outdoors, it was likely intense sun, heat combined with transplant shock.  If indoors, I have no experience with it.  You're doing a good thing by waiting - It's no fun to kill fish.

Allie Wilson said:

 We had strawberries in there but they all died.  I am thinking there was not enough established nutrients for them?

[Jeff S]

I have a 45 gallon tank with no plants growing, just a media bed for filtration. You don't need plants for cycling They don't aid in the cycling process except to remove nitrates. FYI the smaller the system the harder it is to keep the #s right once you're up and running. I have 2 45 gallon tanks and an IBC system with 3 GBs and the aquariums are always needing adjustments where the IBC maintains good #s.

[Allie Wilson]

Hey thanks ya'all! In one of my systems the ammonia and nitrites are both down and nitrates are at good levels.  Looks like I just had to be more patient and I am ready for fish!

[Jeff S]

Happy growing.