Crazy Cycling

[unknowntbeast]

Day 17ish here and some strange things happening. After day 12 ammonia dropped to 0 ppm, so I raised it back up to around 4 ppm, then 2 days later it was back down to 0. So I added more, and three days later (now) ammonia is still around 2.5 ppm. Two days ago pH was at 6.4, now it's at 6 ppm. Just the other day nitrites were in the deep purple range, now they are at zero, and nitrates are around 25 ppm. I've done these test a twice now to double check and they are the same.
I haven't been doing water changes because it's like once a week 1 gallon is evaporated and needs to be readded.
What the blazes is going on?!!?

 

[ellena]

You've had a pH crash. The end products of the cycle are acidic so will eventually lower your pH. At 6, the bacteria can't work. You need to do 100% water change and re-add ammonia. These may become a regular occurance, in which case you can add some bicarbonate of soda (sold for baking, but don't get baking powder-it's mainly flour!) I did have a page which had a guide about how much to add which I'll try and find for you...

Here it is. Of course, you don't know the KH of your water currently, but if you maybe went for an increase of 5? As there are no fish on there, it doesn't matter to much.
This process is adding calcium to the water which will buffer the acid produced by the cycle and keep the pH more stable. Some people's water has enough calcium already, others have to add it.

 

[coldcazzie]

Just wanted to jump in and say thanks ellena for that link - I've bookmarked it in case my pH crashes as well!

 

[Truck]

bacteria can work at PH 6, its just when there is a rapid decrease in PH they become dormant.

as demonstrated by dave spencer

 

[OldMan47]

OK Truck, but this one is a pH crash. Actually it is the carbonate in the sodium bicarbonate that raises the KH. There is no calcium in bicarb. If you use way too much, the pH will stabilize at around 8.0 but most of us don't really want our pH that high. A first choice to control a pH crash is really the water change. Baking soda is the second choice.

 

[unknowntbeast]

Ok so my problem is the pH crash, do a 100% water change? But a pH crash really doesn't explain why nitrites are a 0 ppm when the other day they were at 5+ ppm

 

[waterdrop]

Nitrites are probably at zero because the N-Bacs have had several days to slowly process them without the A-Bacs dumping any more nitrite in, since their growth was stalled when the pH went below 6.2. ellena's info is correct but I agree with OM47 that a 90% water change is the action of choice (a few times) prior to moving on to the bicarb solution.

~~waterdrop~~

 

[unknowntbeast]

Ok Well I just did a 95% water change, I added 4 ppm ammonia, nitrite is a natural level from the water and pH is normal too. Water temp is still only 80 F.

 

[waterdrop]

I forget, were you having heater problems? 29C/84F is our usual temp recommendation. --wd--

 

[unknowntbeast]

No I wasn't having problems, but I've been running at 90 F constantly and there has been no problem with that.

 

[waterdrop]

I think that's too hot.

 

[unknowntbeast]

Ok I will turn it down a tad, but as I said, the bacteria still grew.