Api Kit And Misleading Results

Discussion in 'Freshwater Beginners' started by camste, Apr 23, 2018.

  1. camsteValued MemberMember

    I'm just wondering if anyone has seen a similar issue. Could the ph cause misleading results on other tests?

    I'm cycling an 80 gallon tank, and it seemed to me like things were almost done. My nitrites were down to 0.25, and my nitrates were climbing. Ammonia went from 2 to 0 in a day. Then it all stopped. Ammonia stopped being converted. I read somewhere in a forum after googling that the nitrates could get too high and it could stall the cycle. I did a partial water change, dosed ammonia to 2, and after a day the ammonia was gone again. Nitrites still at 0.25. A few more days went by with nitrites at 0.25, and everything stopped again. I then googled again, and read that the nitrates weren't to blame but it could be the ph. I measured the ph. The tetra test goes down to 5, and it showed 5. So it could have been even lower. I made an 80% water change and got the ph up to 7 (the tap water is 8). But after the water change (I tested immediately) my nitrites were way up. Now we're talking 1-2. The tap water has 0. I can't see how the nitrites can go up after a water change. Could it be that the test kit couldn't handle the ph?

    I dosed ammonia to 2, and this time it took 2 days before it went down, so I guess I hurt the cycle a bit by making the big water change (or maybe it was caused by the ph problem), but it's moving again at least. The nitrites haven't decreased however. And there's algae everywhere. How does that affect the filter? Will the current just flush it away? I've cut the lights to 4 hours now. There's some of the algae which is denser and has a slightly different color than the rest. I just hope it's not cyano bacteria :( Could that out-compete the beneficial bacteria?
  2. jdhefModeratorModerator Member

    Okay...this brings up bad memories for me.

    When your pH drops below 7.0 ammonia starts converting into ammonium. By the time your pH gets down to 6.0, all ammonia has converted into ammonium. While ammonium is far less toxic to fish (some claim it is non-toxic) it is a terrible food source for the ammonia converting bacteria.

    If you have an established bacteria colony, the ammonia converting bacteria will become dormant (for a couple of weeks before starving off). With young bacteria...I'm not sure if it will go dormant or just starve off.

    Once you raise the pH level up towards 7.0, all that ammonium starts turning into ammonia once again. Now your dormant ammonia converting bacteria wakes up and starts converting the ammonia into nitrites. But sadly, during the time your ammonia converting bacteria was dormant, no nitrites were being produced, so the nitrite converting bacteria starved off. So suddenly you have a nitrite spike.

    The reason this bring up bad memories is because unbeknownst to me, having soft water (who knew?) I suffered a pH crash and my pH dropped to the bottom of the API test kit (I thought it was 6.0, but maybe it was 5.0). So all my ammonia turned into ammonium.

    With ammonium in the tank the fish were fine, so I didn't suspect there were any problems. Then on a Sunday morning I did my normal 50% water change. I wake up on Monday morning to find all be 2 of my Rainbow fish dead...it was carnage. I had no idea what happened and posted here about it. The answer I got is the answer I gave you, the pH dropped, ammonia turned into ammonium, nitrite converting bacteria starved off, water change raised the pH, the ammonium turned into ammonia, the bacteria woke up and started producing nitrites and my fish suffocated due to nitrite poisoning. Like I said, bad memory.

    With your pH being 8.0 out of the tap, it is a unexpected that you would have soft water (i.e. low kH & low gH), but you very well may, which allowed a pH drop. I would recommend getting a test kit for measuring gH and kH and seeing where your tap water stands. If your tap water does have low kH and gH levels, you can add some crushed coral to your filter to raise the kH. (That's what I ended up doing and haven't had a problem since).
  3. camsteValued MemberMember

    Omg. Good to know. I had no idea. I knew about the ammonia vs ammonium being dependent on ph, but didn't know that the bacteria don't care too much for ammonium. Frequent ph tests for me from now on then. I haven't run a kh/gh test for a long time (and have since moved to a different part of town, so I don't know if the water comes from the same place), but I believe the water is quite hard. I get white deposits on the dark tiles in the shower and on the dishes and cutlery whenever water is allowed to dry on it.

    So I was actually close, I just ended up destroying it for myself. Well, the waiting game continues then. It could seem the ammonia eating bacteria just went dormant since they were able to start up again right away after the water change (even if it was a bit slow at first). Come on nitrite killers! You can do it! Luckily there are no fish in there, so I have no casualties.

    Thanks for your help :)

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