Big P H Drop On Cycle. Help!

[andy_sheff]

right. Just done a water change. Most of the water, topped up with de chlor and amonia, ile update when there is a change!

 

[waterdrop]

yes, let us know what pH you achieved with the water change

 

[OldMan47]

This is his second water change WD. I got him to try one just a couple of days back. It may well be time to consider sodium bicarbonate to buffer the pH.

 

[waterdrop]

Oh, good to know. I pre-loaded some of the info up there for him, thinking this looked like a case that could go in this direction. KH must be pretty low.

~~waterdrop~~

 

[andy_sheff]

i checked the ph this morning and i checked it just now and its defo gone down from 8 am til now. Its now at 6.4 maybe less! When i did the change i checked it and it was at about 7.4. Thats right this is my second water change with only a couple days in between, whats peoples thoughts on whats happening? Whats best to do? I can see it being 6 or lower tonight.

 

[degsod]

I would put some baking soda in the tank, about 1 tablespoon per 50 litres.

 

[andy_sheff]

the geezer in the fish shop thinks im mad doing this cycle, he recons ph cant drop like this so fast and the amonia must be giving a false reading or making the ph go down, i explained its not done it for first two week so that cant be the case, this baking soda trick, how do you know how much to put in to raise from x ph to s ph

oops, i mean from a ph to b ph

 

[degsod]

the geezer in the fish shop thinks im mad doing this cycle, he recons ph cant drop like this so fast and the amonia must be giving a false reading or making the ph go down, i explained its not done it for first two week so that cant be the case, this baking soda trick, how do you know how much to put in to raise from x ph to s ph

Like most LFS's they either don't know about the fishless cycle or they don't care, after all if it all goes wrong you will be back to spend more cash on useless chemicals etc. Adding ammonia will increase the pH as it is alkaline, the reason that the pH drops is that the ammoia is turned into nitrites then to nitrates which forms Nitric Acid which is a strong acid, therefore the pH drops.

How much to add is like asking how deep is a hole. Its trial and error really, generally the 1 tablespoon per 50 litres is a good place to start.

 

[andy_sheff]

i see, and what ph should i aim for? do i just keep adding it every time it drops?

 

[degsod]

i see, and what ph should i aim for? do i just keep adding it every time it drops?

You need to aim for about pH 7.8

 

[waterdrop]

The ideal pH for the "bacterial growing soup" (which is all you care about before the big water change and getting fish!) is 8.0 to 8.4 which is pretty alkaline. Degsod is giving you the correct info. Its now obvious that water changes are not going to help much for you and no doubt we'd find a very low KH measurement if we bothered to measure. What I recommend doing is to perform yet another 90% water change (with conditioner dosed, say, 1.5x what they tell you) and roughly temp matched if that's easy to do and then recharge the ammonia back to 5ppm and dose the tank with a tablespoon (3 teaspoons) per 50L of water (the accuracy of this is no big deal, so don't sweat the fractions.) Make sure you are using kitchen baking soda (pure sodium bicarbonate) (not baking powder.) Your temp is up at 84F/29C, right?

~~waterdrop~~
edit: ps. degsod is right, the bicarb probably won't nearly raise you up into the 8's and the high 7's will be fine as he's said.

 

[andy_sheff]

got ya. My temp is 85 ish. I have just been to tesco. Bicarbonate of soda, it that the right stuff? I got it any way, if not ile have to hunt round tomorrow.

 

[degsod]

got ya. My temp is 85 ish. I have just been to tesco. Bicarbonate of soda, it that the right stuff? I got it any way, if not ile have to hunt round tomorrow.

Bicarbonate of Soda is the correct stuff. Do a water change as waterdrop suggested and fill backup with your water with 1.5 times the reccommended dose of dechlorinator and add the bacarb.

good luck

 

[waterdrop]

 

[andy_sheff]

so far so good, the ph is staying up and its now processing amonia whithin 24 hours... whats the next step?

i think some of the bacteria is growing on the sand,.. well, blowing about on it, ive removed some today but cant remove it all, will this get eaten when fish are put in there? ive added a few pics... not fully decorated yet, need some things for the righthand side, i have a big bit of mopani to go in.