Ph Crash?

[jaclynl]

I'm almost through my fishless cycle, my nitrites have dropped to 0ppm but it is still taking about 24 hours to fully process.

In the past few days my pH has dropped from 7.8 to 7.2 this morning (API liquid test), should I be concerned about a pH crash? Are there any steps I should take to prevent it from happening?

Thanks,
Jaclyn

 

[Miss Wiggle]

have you got a KH test kit?

no need for concern at 7.2 but keep an eye on it, if it gets down to 7 then do a large water change to bump it up.

 

[waterdrop]

Once you get through the period of the "nitrite spike" as nitrites start dropping to zero within 24 hours, just like ammonia, there is a feeling of relief like the end is near. And indeed it is a good sign that you are surely more than halfway through. Its just good though to realize that often it can take a while for both ammonia and nitrite to get around to dropping within 12 hours (often there is a seemingly stubborn period where it drops in not quite 12 hours and people get frustrated, but its very common and will indeed get past that with some time.) Once they both finally truly drop in 12 hours, we like to have people hang on for a "qualification week" (often just the rest of the week until they get fish on the weekend) because sometimes the filter will still "mini-spike" during that week due to the new bacterial colonies still being more fragile than thought. Often the last minute planning for exactly which fish and whether they will be available that weekend takes time that week anyway!

~~waterdrop~~

 

[jaclynl]

have you got a KH test kit?

no need for concern at 7.2 but keep an eye on it, if it gets down to 7 then do a large water change to bump it up.

My KH reading is dropping, today it is 40ppm. Is it normal for it to drop? Yesterday it was 130ppm.

 

[waterdrop]

Yes, its normal for KH to drop just like pH during a cycle. You'll probably need to either do some large water changes like MW said, or possibly resort to baking soda if the water changes are needed to frequently. Doing a few waterchange-recharge operations in the latter stages of a fishless cycle to kickstart it going again is not uncommon (people with softer tap water usually end up needing this more frequently, whereas people with relatively hard water can often get through the whole process without a water changes.)

When you do your water change its good to do it just like you will do once you have fish, ie. make it a full gravel clean during the water change. That will remove more debris and nitrates that if you just changed water without stirring up the gravel. If you want, test your nitrates shortly after the water change and if they're still high, do another one right away. Be sure to use conditioner and rough temperature matching for these water changes and then after the final one is done be sure to top your ammonia back up to roughly 5ppm and then wait an hour before doing another set of readings for your logbook.

~~waterdrop~~

 

[jaclynl]

Yes, its normal for KH to drop just like pH during a cycle. You'll probably need to either do some large water changes like MW said, or possibly resort to baking soda if the water changes are needed to frequently. Doing a few waterchange-recharge operations in the latter stages of a fishless cycle to kickstart it going again is not uncommon (people with softer tap water usually end up needing this more frequently, whereas people with relatively hard water can often get through the whole process without a water changes.)

When you do your water change its good to do it just like you will do once you have fish, ie. make it a full gravel clean during the water change. That will remove more debris and nitrates that if you just changed water without stirring up the gravel. If you want, test your nitrates shortly after the water change and if they're still high, do another one right away. Be sure to use conditioner and rough temperature matching for these water changes and then after the final one is done be sure to top your ammonia back up to roughly 5ppm and then wait an hour before doing another set of readings for your logbook.

~~waterdrop~~

Should I do the water change even with my pH where it is at 7.2? I just tested again. I added ammonia about 10 hours ago and it is already back down to 0ppm, the pH is still around 7.2

I was curious so I check my tap water and the pH is impossible to read, the API test kit has shades of brown and purple for the high range pH and mine is bright pink! any idea what that means?

My Nitrites are still dropping down to zero but it's taking a long time, should I assume things are going okay for now or should I proceed with a water change?

Thanks,
Jaclyn

 

[OldMan47]

My first guess about bright pink is that you accidentally used the nitrite drops instead of the pH. What reading do you get using the normal range for pH on your tap water? If it is less than 7.6, there is no need to try to use the high range.

 

[jaclynl]

My first guess about bright pink is that you accidentally used the nitrite drops instead of the pH. What reading do you get using the normal range for pH on your tap water? If it is less than 7.6, there is no need to try to use the high range.

I used the regular pH and my result was dark blue, darker then 7.6 on the card. So I did the High pH test. I just repeated the test and got pink again, although this time it might look a little closer to the 8.2 reading, it is still much more pink than the card though.

 

[backtotropical]

Should I do the water change even with my pH where it is at 7.2? I just tested again. I added ammonia about 10 hours ago and it is already back down to 0ppm, the pH is still around 7.2

It would be prudent to proceed with the water change now before any problems occur, I would suggest.

To try to help you understand, kH is like a buffer for pH, so while kH is high it will hold pH very stable. However kH will be depleted by acids which are a by-product of cycling. If kH is allowed to be depleted by these acids and fall to a low level, there is nothing left to hold the pH stable and the acids start to pull the pH down.

Basically, because your kH is dropping, if you don't carry out a water change to bump the kH back up again, the pH will start to fall sooner rather than later. If the pH is allowed to fall, the cycle will stall. Therefore, a water change would be the best idea.

Hope that makes sense. It is 2:30am after all......

Cheers

BTT

 

[OldMan47]

Not a bad description for half asleep BTT.

 

[jaclynl]

Okay... I did a 50% water change about an hour ago (it did not go well...I got water everywhere! including all over my nearby books).

I refilled the tank with warm, conditioned water. I checked Nitrates, they were down to between 0-5ppm, I added ammonia to get back up around 4-5ppm.

Now here are my readings an hour later.
Ammonia = 4ppm
Nitrites = 5+ ppm
Nitrates = 0-5ppm
pH = 8.0
KH = 80ppm

Hopefully I'm back on track

 

[OldMan47]

It looks like you have recovered some buffer now JaclynL.

 

[jaclynl]

Okay it's been 12 hours since my last readings

I went out and bought an actual liquid KH test because I wans't satisfied with the strips (all I could find before), here are my current readings

Ammonia = 0.25ppm
Nitrites = 5+ ppm
Nitrates = 5-10 ppm
pH = 7.4
KH = 2.5 dH (tap water is 5 dH)

As you can see pH is dropping....buffering capacity is low. Should I do another water change or switch to baking soda?

 

[jaclynl]

Another 24 hours have passed and here are my readings:

Ammonia = 0ppm
Nitrites = 5+ ppm
Nitrates = 5-10 ppm
pH = 7.4
KH = 2 dH

KH is dropping still but pH is the same as last night...

Any suggestions??

Thanks

 

[waterdrop]

Once KH drops below 4dH and the acids are still building up from cycling, the pH will probably not hold for long.

Was there a physical/logistical reason for only doing a 50% change? (of course, saving books would be a good reason ) During fishless cycling you want to do the largest percentage water change possible, since you are trying to accomplish a chemistry change and there are no fish present.

Since your pH is quite high and your tap KH is 5dH a water change is still quite a good option for you I would think.. not sure if the tank is large or exactly what water changing problems you are having (perhaps we should have a discussion of hoses to make a water change easier?)

~~waterdrop~~