Ph Crash During Fishless Cycle

[tunerhead24]

Im at week 3 in my fishless cycle and today when I did my daily water test i noticed my PH reading is 6.4 !!! The tank im cycling is a 55 gallon, my ammonia reading is 1 ppm and nitrite is also 1ppm as of today. Should I do a water change ? I really hope I dont have to start all over again.

 

[doresy]

do you have bogwood in there?

 

[tunerhead24]

yes i do have bogwood but i never seen my ph so low during the cycle

 

[backtotropical]

Hi Turnerhead,

The good news is you shouldn't have to start your cycle again.

The pH falling during a fishless cycle is quite normal and nothing to worry about so long as you notice it and take the appropriate action. Bogwood can cause the pH to drop, but the fishless cycle itself is probably the cause in this case.

What is the pH of your tap water? If it is higher than 6.4, do a 50% water change and then test the pH in the tank again. You should aim to keep the pH in the tank the same as the pH from the tap. If the tank pH continually drops, that indicates that your water lacks buffering capacity (carbonate hardness), but this can easily be fixed if necessary.

You might also need to top up with ammonia again after the water change. If ammonia is at 1ppm, and you change 50%, ammonia will be around 0.5ppm so an ammonia top up is probably due in any case.

Keep us updated on your progress.

BTT

 

[tunerhead24]

should i test the tap water right from the faucet or let it sit for 24 hours like some people mentioned in other topics?

 

[waterdrop]

Let it sit before your pH test. If I'm remembering right, often CO2 will be elevated coming out of the tap and you'll want that to equalize with the air prior to getting your pH reading.

~~waterdrop~~

 

[tunerhead24]

Well while I wait I guess I'll let you guys know how my fishless cycle is progressing. I added ammonia on January 3rd to 5 ppm, the next day it dropped down to 3 ppm right away I raised it back up again. Nothing happened for about a week, ammonia stayed exactly at 5 ppm. Here are my stats......

1/10/09
NH4 - 2 ppm
NO2 - .25 ppm

1/11/09
NH4 - 2 ppm
NO2 - .25 ppm

1/12/09
NH4 - .5 ppm
NO2 - .5 ppm

1/13/09
NH4 - .25 ppm
NO2 - .5 ppm

1/14/09
NH4 - 0 ppm Raised to 5 ppm
NO2 - 1 ppm

1/15/09
NH4 - 2 ppm
NO2 - 2 ppm

1/16/09
NH4 - .5 ppm
NO2 - 2 ppm

1/17/09
NH4 - 0 ppm Raised to 5 ppm
NO2 - 2 ppm

1/18/09
NH4 - .25 ppm
NO2 - 5 ppm

1/19/09
NH4 - 0 ppm Raised to 5 ppm
NO2 - 5 ppm

1/20/09
NH4 - 0 ppm Raised to 5 ppm
NO2 - More than 5 ppm

1/21/09
NH4 - 0 ppm Raised to 5 ppm
NO2 - More than 5 ppm

1/22/09
NH4 - 0 ppm Raised to 5 ppm
NO2 - More than 5 ppm

1/23/09
NH4 - 0 ppm Raised to 5 ppm
NO2 - More than 5 ppm

1/24/09
NH4 - 1 ppm
NO2 - 1 ppm

At the beginning of the cycle PH was 8.4, I would check it about twice a week. The Ph would bounce around from 7.8 to 8.4 but never under the 7.8 reading. When checked my water stats today I noticed ammonia didn't drop to zero like its been doing for the past week or so, I got suspicious and decided to check PH. I got a reading of 6.4 and I started to panic knowing that a PH reading below 6 would cause a cycle to stall ! By the way my Nitrate levels are between 40-80 ppm so nitrite must be getting processed right? Let me know what you guys think......

 

[OldMan47]

It looks like your cycle is stalling. As BTT suggested, a 50% water change would probably help a lot and you should probably top off with ammonia afterward.

 

[waterdrop]

Hi Tuner,

You should have been able to measure the tap pH by now to answer BTT's question. I'm sorry I probably implied last night that the wait for getting a good reading should be as long as you mentioned but I actually can't remember and its probably really only a pretty short time that needs to be waited (half hour?) Maybe someone will see this...

Anyway, that's your next step. The most desirable thing is for your tap pH to be high enough, as BTT says, which I suspect might be true for you given where you started. If that's the case then you are perfect candidate for a nice thorough gravel-clean (or two!) where you take out a large percentage of water and then recharge with ammonia. I'm almost always too lazy to even turn off my cannister filter and just remove water down to just above the intake, so it can still be running while I'm changing water. You can even refill and immediately do it again if you want to get the nitrate level way down (which is supposed to be good for encouraging faster N-Bac growth).

A water change in the later stage of fishless cycling (the "nitrite spike" stage, which you certainly appear to be in) is actually great for giving you a chance to practice what will be your weekly water change process but since you don't have fish in there its a little easier, not having to worry about sucking them up! Note that there will be a "pause" in the cycle for a day or two as the bacteria adjust to this change you've made, but you have to do it if your pH has crashed and its better of course than having it sit there "stalled."

~~waterdrop~~

 

[OldMan47]

His pH started in the 8s WD. A water change should definitely help by bring the pH back up unless the water supply has changed.

 

[waterdrop]

Yes, I had remembered that, was just being cautious and trying to build on the direction he and BTT had taken. Agree we have every reason to suspect the tap water will bring it up just fine.

~~waterdrop~~

 

[tunerhead24]

Hey guys i did two PH tests, one directly from the faucet which gave me a reading of 7.6 and the other was after a 12 hour wait which gave me 7.0 . I did do a 50% water change last night because i got so impatient and i topped off ammonia to 5ppm but i checked my water stats this morning and all i got was bad news!

NH4 - .5 ppm
NO2 - 0 ppm
NO3 - more than 5 ppm but less than 10 ppm (api test kit)
PH - 6.0 !!!

lol now what??

 

[backtotropical]

Well your cycle certainly hasn't stopped, thats for sure. Ammonia is still processing, and the lack of nitrite indicates that is processing too. It actually sound like you are almost cycled, but just having a slight pH problem at the moment.

Try another 50% change and then test the pH again. I am now wondering how your pH was originally over 8, when your tap pH is around 7. Maybe the water company are messing about with it just now.

If the pH keeps dropping, it's a simple case of adding bicarbonate of soda to the tank to raise the pH until the cycle completes.

 

[Emily in CA]

I am going through exactly the same thing with a 45 gallon tank fishless cycle. I am beginning my third week of the cycle using ammonia (10% ammonia hydroxide from ACE Hardware) and bacteria from my pond filter and all of a sudden my PH has crashed (6). I just did a partial water change and my PH came back up to 7. My nitrites are 2ppm and nitrate is 5 ppm after the water change. I have read that ammonia hydroxide can mess with the ph. Will baking soda cause other problems if I use to raise the ph?

 

[tunerhead24]

I am going through exactly the same thing with a 45 gallon tank fishless cycle. I am beginning my third week of the cycle using ammonia (10% ammonia hydroxide from ACE Hardware) and bacteria from my pond filter and all of a sudden my PH has crashed (6). I just did a partial water change and my PH came back up to 7. My nitrites are 2ppm and nitrate is 5 ppm after the water change. I have read that ammonia hydroxide can mess with the ph. Will baking soda cause other problems if I use to raise the ph?

Welcome to TFF ! I was just about to ask the same question also how much baking soda should I use and can I use the arm & hammer brand?