Cycled Tank Dead From Low Ph Level?

iceprizm · May 26, 2009

i use to have a fully cycled tank. i used my normal tap water that varies from PH of 7.5-8.0. i was planning on making a tetra schoal tank, so I did a large water change and filled with RO water PH of 6.4. all the bacteria i had is gone, and i have started cycling all over again. it has been over a week with no reduction of ammonia or any rise of nitrites. i am wondering if the 6.4 water PH would have been less than ideal for the bacteria? it is the only reason i can think of for losing my bacteria colony.

Bobtastic · May 27, 2009

I've done a fish-in cycle with water with a pH of 6 - 6.7. The pH of the water from the tap is 6 and I've had to use a pH Buffer (7) initially and then crushed coral more recently to increase it a little bit.

I understand that the A-bac starts to stall around the pH6 mark. But they shouldn't have died off...

minxfishy · May 27, 2009

If the tank is re-cycling (and I cant offer an explanation for that Im afraid without more information) then at 6.4ph it wont be doing anything, you need to raise the ph level, either with a large water change with tap water (not RO) or by adding baking soda/powder to raise it. Cycling required ph between approx 7.4 - 8.2, the higher end of the scale seems to be best, temperature 80 or above too.

Out of interest, why were you trying to change the ph for tetras by adding RO? They would have been fine, properly acclimatised to your tank water.

Bobtastic · May 27, 2009

I never really understood that, why does the pH have to be 7.4-8.2 during a fishless cycle. But it the pH can go as low as 5, depending on the species, whilest fish are in the tank?

minxfishy · May 27, 2009

Dont ask me why, thats just the way it works, its all too scientific for me, there is a discussion on it somewhere in the science section about it.

iceprizm · May 27, 2009

well the ph of the tank is now 7.5. I added some water from my live bearer tank, so the ph is prob. higher now. temp is also set to 80.

when i got the tank ready for fish i took out all the bac. pop. media, put it in a bucket with some tank water and added a little ammonia. after the weekend i tested the water in the bucket and found ammonia still there with no nitrites. i added the media to the ro filled tank, dosed with ammonia and found the media no longer is converting ammonia.

so would tetras be ok with a ph as high as 8.5? i think that is as high as my tap water goes.

also i have noticed that ammonia has a very high ph to it. i add it to the tank and the ph skyrockets, once the ammonia processes the ph will lower consideribly. went from a 6.4 tank to 7.5 with nothing but the dosing of ammonia.

maybe i would be better off with tap water instead of RO. and maybe looking for different fish. its a 75 gallon btw. and no i dont want another tank with livebearers.

jonnyf84 · May 27, 2009

your cycle will stall at PH levels of 5.5 and below, if your PH is above this then it is not the culprit. Overdosing ammonia can cause serious problems, dose 5ppm per day max, when that 5ppm has been converted don't put any more in until 24 hours after your last dose.

snowflake311 · May 27, 2009

I just posted a thing about this. My ph crashed when my nirtites stared to take off. Yes the crash stalled my cycleing. When you first put the live filter stuff in to seed the tank did you feed it ammonia? If not it all might have died off. I have been cycling my tank for 5 weeks now my plants love it and are growing like crazy but I'm getting annoyed.

Make sure you add the same amout of ammonia everyday don't increas or decreas it. I increased mine and all he'll broke loose. Also keep an eye on you ph. I would not use RO water since this tends to soften Water. Just use tap for now.

iceprizm · May 27, 2009

snowflake311 said:
I just posted a thing about this. My ph crashed when my nirtites stared to take off. Yes the crash stalled my cycleing. When you first put the live filter stuff in to seed the tank did you feed it ammonia? If not it all might have died off. I have been cycling my tank for 5 weeks now my plants love it and are growing like crazy but I'm getting annoyed.

Make sure you add the same amout of ammonia everyday don't increas or decreas it. I increased mine and all he'll broke loose. Also keep an eye on you ph. I would not use RO water since this tends to soften Water. Just use tap for now.

my tap water is extremly soft 0GH. i dont know why my media went dead but it did. it never went more than 24 hrs without ammonia. i also swiped one of my bio-wheels from my established tank and added it to new tank......that was over a week ago and i still have no reduction in ammonia levels. :crazy:

snowflake311 · May 28, 2009

I'm getting annoyed with my tank too. It's been 5 weeks and my nitrites Are still high a week ago they were going down. My ph has been crshing too. So I feel your pain. I did A fish in cycle it went way better then this fishless one. Oh well it just takes time good luck with yours. Keep that ph up and make sure you feed the tank the same amount every time you add it. That is where I messed up.

jonnyf84 · May 28, 2009

i feel your pain guys, i had to wait longer than expected for some rare fish, i had to keep there new tank running for 4 months with no fish as i didn't want to introduce any diseases, it was a absolute nightmare. My KH is also 0 (well 0.5 maybe) so unless you have a established tank then PH will drop regardless, add this to a four month cycle and it was just horrible, i got through so much bicarb and 3 laborette kits!!!! But it was worth it in the end and i now believe i have learnt everything there is to know about cycling. If i had to give one bit of advice it would be never add more than 8ppm of ammonia, this triggers a over-cycle and when you come to add fish all your work will be wasted and you'll have to start again, dose 5ppm at the same time every day.

iceprizm · May 28, 2009

jonnyf84 said:
i feel your pain guys, i had to wait longer than expected for some rare fish, i had to keep there new tank running for 4 months with no fish as i didn't want to introduce any diseases, it was a absolute nightmare. My KH is also 0 (well 0.5 maybe) so unless you have a established tank then PH will drop regardless, add this to a four month cycle and it was just horrible, i got through so much bicarb and 3 laborette kits!!!! But it was worth it in the end and i now believe i have learnt everything there is to know about cycling. If i had to give one bit of advice it would be never add more than 8ppm of ammonia, this triggers a over-cycle and when you come to add fish all your work will be wasted and you'll have to start again, dose 5ppm at the same time every day.

interesting. while my GH is 0 my KH is actually high.....7 degress or so. when i cycled my 55 last year once all the amm and nitrit were processed in 24 hrs. i started doubling the amm dose. thinking i would get as much bac established as possible. i added lots of fish at one time and have never seen even a trace of amm.

on my 75 i was doing the same thing adding lots of amm. when i put the filters in the bucket i just added a splash of amm, did bother to measure it. thinking back i prob only need a couple of drops. maybe massive ammounts of amm will kill the bac? i then put the bucket in my garage, so it prob saw temps over 90 c.

ok leason learned no more double dosing amm.

jonnyf84 · May 28, 2009

when i cycled my 55 last year once all the amm and nitrit were processed in 24 hrs. i started doubling the amm dose.

Exactly what i did

maybe massive ammounts of amm will kill the bac?

It doesn't kill the bacteria it causes the bacteria to becomes mutated(for lack of a better word), it will keep processing the ammonia but when you come to add fish and therefore drastically reducing the amount of ammonia the whole system will crash.

ok leason learned no more double dosing amm.

indeed, me to, when i think back i don't know why i kept dosing more and more ammonia, i guess that once the ammonia had been converted within 5 or 6 hours i thought to myself that there is no more ammonia so if i don't dose more then the beneficial bacteria would die - oh how wrong was I!!!!!!!!!!!

snowflake311 · May 28, 2009

Funny how we can manage to mess up a fishless cycle. I was doing fine only adding a little bit of ammonia then i added too much ammonia once my nirtites were going up. I messed up everything. But my plants are loving it.

Glad to see I'm not the only one that messed up a fishless cycle. I feel like I have learned a lot too.