Ph Lowered During Cycle

[**sarahp**]

My ph dropped through the floor - from 7.6 - 6.0 - whilst fishless cycling. I noticed this on Monday night but because we have had staff off sick I've been working stupid hours and not had chance to do a water change until last night.


So - my question - will this drop in ph just have made the bacteria go dormant or will it have killed them off? I had a 1ppm ammonia 0ppm nitrIte reading all through from when I noticed the low ph until I did the water change - but I did not add more ammonia until after the water change.

Also I lowered the temp from 30+ to 28 as I think it may be upsetting some of my plants.

Anyway the result it that at 10.30pm last night my ammonia was 4ppm, nitrIte 0ppm now (12.30pm) my ammonia is 0.25ppm and nitrIte is 0.5ppm so I havent messed up my cycle have I

 

[rdd1952]

The low pH won't kill off your bacteria but bacteria reproduction severely slows or stops as pH levels get near of below 0. I would suggest doing a water change to get the pH back up to near 7. A 75% water change should be fine, just don't rinse the filter.

 

[mark.w.jones]

Sounds fine, just raise your ammonia level back to 5ppm and away you go again. Keep testing ammonia and nitrite every day. pH does swing around a bit when cycling but shouldn't cause to many problems unless it gets much lower.

 

[Aphotic Phoenix]

pH of 5.5 is when nitrifiying bacteria go dormant. Doing a partial water change to re-establish the buffer wouldn't hurt...just measure the ammonia level after the change, and redose accordingly.