FISHLESS CYCLING: Drop in Ph

[thegundog]

Have encountered a PH DROP in todays readings and would ask for advice - is it time to change the water?

Here are my latest parameters -

Oct 18
PH (8.0) - Amm (4.0) - Nitrites (2.0) - Nitrates (40)

Oct 19
PH (8.0) - Amm (.25) - Nitrites (5.0) - Nitrates (40)
Dosed tank with 4ml of ammonia to bring ammonia level back to 4.0

Oct 20
PH (7.4) - Amm (.50) - Nitrites (5.0) - Nitrates (160)
Dosed tank with 4ml of ammonia to bring ammonia level back to 4.0

Oct 21
PH (7.4) - Amm (.25) - Nitrites (5.0) - Nitrates (160)
Dosed tank with 4ml of ammonia to bring ammonia level back to 4.0

Oct 22
PH (7.4) - Amm (..25) - Nitrites (5.0) - Nitrates (160)
Dosed tank with 4ml of ammonia to bring ammonia level back to 4.0

Oct 23
PH (7.0) - Amm (.25) - Nitrites (1.0) - Nitrates (160)
Dosed tank with 4ml of ammonia to bring ammonia level back to 4.0

Oct 24
PH (6.4) - Amm (1.0) - Nitrites (2.0 - 5.0?) - Nitrates (160)


I have a 29 gallon, moderatly planted.

I am on good ole well water and I've tested my tap water twice as follows:

Ph (7.2) - Amm (0.0) - Nitrites (0.0)

 

[librarygirl]

Yep, definitely time for a massive water change to get PH back up. The cycle may have taken a small hit due to the PH drop (nitrification seems to have slowed slightly as ammonia hadn't dropped as quickly) but it should bounce back in a day or two.

 

[thegundog]

Fishless cycle: since posting the above parameters I have experienced two PH drops warranting 50% water changes.

Is this normal?

Why does the ph drop so significantly?

 

[librarygirl]

Yes it's normal for PH to drop during cycling. I'm sure someone else can explain it better than I and I still don't have a total understanding of the science behind it but the bacteria are using the buffers in the water; your water must be low in alkalinity. Just do a water change any time it starts dropping. If it does it a lot you can add a small amount of crushed coral in a mesh media bag or new clean nylon stocking and put it in your filter to help buffer the water.

 

[eco23]

Librarygirl has it right. During cycling (actually the entire time you have an aquarium) the beneficial bacteria consume alkalinity much in the same way as they use ammonia and no2 as a food source. Since the alkalinity / buffers are what holds the pH stable...as these buffers are used up it exposes the water to potential pH fluctuations. The bacteria also excretes acidic waste...and since the buffers are gone, there is nothing to prevent the pH from dropping.

Normally a good water change schedule will refresh the alkalinity and prevent this from happening...but if your water naturally has low alkalinity it can't keep up with the rate it is being consumed. In those situations it's a good idea to use a natural product like crushed coral or aragonite sand which slowly dissolve into your water providing the alkalinity your water is lacking.

 

[thegundog]

Tests from today:

Ammonia - 0

Nitrite - 0

Nitrate - 160

Ph 7.0 - 7.2

Dosed to 4.0 ppm ammonia following ECO's cycle narrative.

Crossing my fingers!!!!!!!!!

 

[eco23]

So the nitrItes have spiked and are now dropping to zero on their own within 24 hours? If so...you may be done

Since you just dosed the ammonia back to 4ppm, check again this time tomorrow and if you're at zero ammo and zero no2...it's time for fish . Just remember to turn down the heater (if you've got it cranked up) and get the no3 below 20.

I look forward to tomorrow's update.

 

[thegundog]

Tests from today:

Ammonia - 0

Nitrite - 0

Nitrate - 160

Ph 7.0 - 7.2


I think I'm FISHLESS cycled!

Now my next step as I understand it is to perform a massive water change to remove the Nitrates, which I will do later tonight.

I have two questions:

1. After performing the water change how much ammonia should I add to keep my bacteria alive?
2. It may take me a few days to locate and purchase my initial stocking. How much ammonia should I continue to add DAILY until I have added fish.

Thanks!!!!!!

 

[eco23]

I just posted this on another thread...but it's the exact same thing I'd put here...so forgive my copying and pasting

--------------------

That's great news!

If it's going to be a significant amount of time before getting fish, there's nothing wrong with keeping it at 4ppm. The only downside is that the no3 will jump back up and you'll have to do more water changes to get them down before stocking.

If it's only gonna be a couple days, you can keep it fed with just around 1ppm every day. It takes several days before the bacteria begins adjusting to the lower level of ammonia...so as long as you don't let it go too long at the low dose it'll be fine.

One thing I'd do is turn down your heater now so you don't forget. You don't want to get new fish just to cook them when they get there

Keep us posted and remember that we require pictures