Backyard Aquaponics
A place to discuss aquaponics

Hello everyone,

I've been cycling for over a month and am having trouble. Hopefully someone out there knows the answer.

As soon as my system was set up I planted a bunch of plants, added some liquid agae to my tank, and started adding a little ammonia every day until nitrites appeared. When nitrites appeared I cut the amount of ammonia I added daily in half. Finally nitrates appeared so I stopped adding ammonia and checked my nitrite level every day, waiting for it to drop so I could order my fish. I thought this was the standard formula for fishless cycling, but my nitrites have refused to disappear (the test tube shows deep eggplant purple still), and all my plants have died.

What did I do wrong?

So over the last three weeks I've replaced about 90% of my water several times, but to no avail.

Any ideas?

Any advice is much appreciated,

Thanks!

Hi RJT, welcome to the forum

Did your nitrates continue to go up after you initially saw some? What are your readings for Ammonia, Nitrite, Nitrate, pH and Temp at this point? Info on what the readings were before would be helpful too.

What scotty said and changing your water was a not too good an idea; BTW what is liquid agae (Seaweed fertilizer )?

Thanks guys for the quick responses. Here are my levels:

ammonia: 0 ppm
pH: 8.2
nitrites: >5 ppm
nitrates: 20 ppm
temperature: I live in southern California, so I don't really even think about water temp. It feels like mid-high 60s.

I'm guessing it was the high pH level that killed the plants, but does that affect the nitrite level too?

I added liquid seaweed because that's what Sylia Bernstein's book recommended (maybe it was supposed to be instead of ammonia?). And I changed out the water a few times in an attempt to dilute the nitrite level - though no levels changed.

As far as the readings before, I was adding enough ammonia to get it between 2-4 each day - it dropped back to 0 as soon as I stopped adding it though. After a couple of weeks nitrites, and then nitrates crept up, at which point I cut the ammonia. The pH was high once I started cycling - probably at around 7.6 - but I had read that it was normal for it to spike while cycling so I wasn't concerned.

pH is too high. Nitrobacter won't survive above 8.0. Your plants are probably dying due to nutrient lockout due to the high pH.

Nitrobacter grows up to pH 8.5 so pH is not the issue, I agree with the nutrient lockout though - https://en.wikipedia.org/wiki/Nitrobacter

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Most liquid seaweed doesn't contain much nitrogen. Your plants probably had some nutrient problems because of the high pH, in particular, Iron would be unavailable at that pH and the new leaves would turn yellow. This is why chelated iron gets used, the Fe-DTPA version is available at higher pH's and is what most people use. Another way around the high pH is to spray on the iron solution.

Check your tap water with the nitrite test kit and see if you get a reading just as a check and to verify it's working. If you get a reading and are on city water I'd call and find out from the city if that's normal (they probably test for this as part of the permitting process)

As far as the nitrite processing. You have or had some going but I'm not sure where your system is at right now. If the water change was done with chlorinated or chloraminated water you may have to start cycling from scratch. I doubt this is the case but it's possible . It's not all that strange to have a system take a full month to cycle and as sleepe said the water changes aren't always a good idea (it really depends on if you put so much ammonia in that you somehow inhibited the process).

If you don't have any fish in the system, I'd leave it to go and let the nitrites finish coming down (soon if the bacteria haven't taken a hit). If that works give it a drop or two of ammonia and verify that you haven't knocked out the first part of the cycle somehow. When the systems ready, the whole conversion process should be done pretty quick. TCLynx post here might help - http://www.backyardaquaponics.com/forum/viewtopic.php?f=11&t=6809

I'd tuck some new plants into the grow beds as well. Get yourself some chelated iron for now and if you see any plant problems just start a thread and post some pics, someone will probably recognize what's going on and let you know what to do. FYI - Potassium is also a common problem nutrient in early systems.

Okay I've added some "pH down for hydroponics" and got the level back down to 6.8-7.0. But does the pH level have something to do with the nitrite level not going down? When I've replace the water I've been careful to spray wide from above in order to off-gas as much chlorine as possible. But either way the nitrite and nitrate levels are still stuck way high. What does cycling from scratch entail if those bacteria are already present? Isn't cycling the process of attracting those bacteria?
So whether or not I put so much ammonia in that I inhibited the process, would my best bet be to just sit tight and wait for the nitrite level to decrease?

Everyone else seems to be able to take questions one at a time (ie insert comments) but I always screw it up, however;

Ph nitrite not going down - not at those levels.
Is that chloramine or chlorine? Two different sterilizers.
The bacteria are everywhere, they need o2 food and a surface on which to multiply
Stop changing water out, increase the o2 if possible and stick some plants in.
Sit tight and stop screwing with it; at least you are not killing fish which I really dislike (I also like some bacteria and plants but you have already done your dash on that one)

k thanks everyone