Ph Keeps Dropping

[craigieboy01]

Hi all, I'm currently doing a fishless cycle in my Fluval Edge, after noticing my cycle had stalled, i realised my Ph was too low at 6.0 (Api master test kit), so i done a large water change on Tuesday 31st and brought my Ph up to 7.6 and added the relevent ammount of Ammonia, after testing this morn my Ammonia has dropped to 0.50ppm, my Nitrites are still 0, should i not be showing more signs of Nitrite? I have also noticed my Ph has dropped to 6.6, why is my Ph dropping? Dont want to keep doing water changes to bring the Ph up as its stalling my Cycle.Any suggestions of what i'm doing wrong? I'm nearly 3 months into a Cycle which should be done by now, getting fed up.

 

[Ryefish]

i am having the same PH problems with my fishless cycle. It kept dropping from 7.2 to 6.4 overnight and getting lower every single night after, so i had to carry out 90% water changes every second day - annoying! I topped the PH up to 8 using Bicarbonate of Soda and it seemed to kick start everything all happy again.

Do you have a day-by-day diary on the forum of your whole cycle data? Im not able to give advice on why your Nitrites are at 0 but somebody else should be able to


ETA: are your Nitrites still blue? if you put the drops in the test tube do they stay blue when they hit the bottom?

 

[craigieboy01]

i am having the same PH problems with my fishless cycle. It kept dropping from 7.2 to 6.4 overnight and getting lower every single night after, so i had to carry out 90% water changes every second day - annoying! I topped the PH up to 8 using Bicarbonate of Soda and it seemed to kick start everything all happy again.

Do you have a day-by-day diary on the forum of your whole cycle data? Im not able to give advice on why your Nitrites are at 0 but somebody else should be able to


ETA: are your Nitrites still blue? if you put the drops in the test tube do they stay blue when they hit the bottom?

Hi Ryefish, Yes they stay blue when they hit the bottom, I have only had 1 Nitrite spike about 6 weeks ago, any idea how much Bicarbonate i should add to bring it up? I have a 23 litre tank (6 Us Gallon) I have kept a written log, havent posted it on the website.

 

[craigieboy01]

Is Bicarbonate of Soda called Baking Soda in the UK?

 

[Essjay]

Mine's called bicarbonate of soda (Supercook brand) and I'm in the UK. You'll find it in the home baking section of the supermarket next to the flour. It normally comes in a round plastic tub. Make sure it's bicarbonate of soda, or possibly baking soda and not baking powder - that's different.

 

[Ryefish]

Yeah. If you are in the UK you can get tubs of Bicarbonate of Soda from the supermarkets in the baking section. Just don't get 'Baking Powder'.

I added it in level teaspoon amounts, left for about half hour to let it mix in properly and tested, repeated again until it was at 8.


The diary might help other more experienced (im not even finished my first cycle yet lol, which is why im reluctant to say things other than what ive experienced myself) people figure out why your cycle is so slow and possibly stalled

 

[craigieboy01]

Mine's called bicarbonate of soda (Supercook brand) and I'm in the UK. You'll find it in the home baking section of the supermarket next to the flour. It normally comes in a round plastic tub. Make sure it's bicarbonate of soda, or possibly baking soda and not baking powder - that's different.

Thanks essjay, will go and get it now, do u know roughly how much i should be adding to a 23 litre tank?

 

[Essjay]

Start with half a tablespoon (ie half a 15ml spoon), then increase to one and a half if the half isn't enough. Dissolve it in a bit of tank water in a tub before adding to the tank.

 

[OldMan47]

A half tablespoon should definitely raise the pH in a small tank like that. I would start smaller and dissolve the material in a bowl outside the tank. That way I could stir vigorously to get a good mix without threatening to splash half the water out of my tank.

 

[craigieboy01]

Thanks everyone, I will add some and let yous know how i get on.

 

[craigieboy01]

Put a level Teaspoon in half an hour ago, checked Ph, its up at 8 so hopefully that should keep things ticking along, What is th best Ph for Fishless Cycling?

 

[OldMan47]

The nominal ideal pH is around 8.4 but anything over 7.0 will do fine.

 

[craigieboy01]

The nominal ideal pH is around 8.4 but anything over 7.0 will do fine.

Thanks OldMan47, i will keep a close eye on the Ph over the next week, Is their a reason for the sudden drop?

 

[fish_tank0311]

If you have driftwood in your tank, that can lower your pH, but it lowers so quickly and dramatically because your carbonate hardness (kH) is too low. kH is a measurement of how much calcium etc is in your water, and the higher your kH is the better it will buffer the water from pH from changes. (At least this is what my local fish specialist has told me) Oldman probably could verify that for you.

 

[waterdrop]

Yes, this is correct. As a practical matter, a KH kit will give a number to the amount of "buffer" the water has, allowing it to withstand pH change. Below about KH=4 it can be expected that the pH may make a quick drop at any time, stopping the cycle.

As a technical matter, KH is supposed to refer to Carbonate Hardness and should only be measuring the carbonates (HCO3-) (also known as Temporary Hardness because it can be boiled out) but it turns out that our kits actually measure Total Alkalinity, which is a good surrogate for carbonate hardness in our situations and so some of the general hardness aspects (Ca and Mg for instance) may indeed be a bit involved, but technically those should be mostly involved in GH (general hardness) measurements.

None of this matters to you as long as you make large water changes when the cycle is in danger of crashing or has just crashed.

~~waterdrop~~