pH just keeps dropping...but WHY?

[Henry405]

What is your temperature at? a lower temp means higher oxygen in the water, if you can try to lower it a bit and see if theres an improvement.

 

[Kurt_Nelson]

Well I went away for two weeks and disaster the tank leaked a little and my
Dads answer was to unplug everything, no water movement, heater, light, skimmer.... Anyway the pH was at 7 and I only have a snail left, pretty much everything else is dead, ...

Wow... that's bad news. I have to agree, if I was in your shoes I'd probably just drain it and start over.

 

[RYANLAWRENCE]

It seems like you might have not been getting enough oxygen to the surface of the water? Did you have a glass lid covering your tank? When carbon dioxide and water mix, they form carbolic acid, and acids lower the pH. I would try lowering the temperature and going "hoodless" on your new tank

 

[Sebastian_Troy]

@Henry
The temperature is 25C, also how could low oxygen cause low pH, like Ryan says its CO2 which dissolves to form carbonic acid...

@Ryan
I have a raised metal hood with my
Lights installed inside it, I doubt it can be restricting airflow too much, also my two power-heads are practically pointing straight up at the surface now to agitate it and increase gas exchange

The only thing left for me to suspect as the cause is my homemade live rock, however can anybody tell me how they can lower the pH when they are made with highly caustic high pH cement, and needed to be cured to bring the pH if the rocks Down!

 

[thincat]

What is your KH? With that much die off That through off the ability to buffer your water. Kh goes down and the water brings the PH down. Sorry for your loss.

 

[Henry405]

I thought you had fish in the tank already, sorry. Fishes consume oxygen and releases co2, so if theres a high temperature, oxygen will dissolve less in the water thus increasing the ratio of co2 to oxygen in the water which might have lowered the pH.

 

[Gregcoyote]

I suspect the ph test kit as well. Get a calibrated meter or liquid test kit when you start over. I also would be sure the rocks are not leeching something into the water. Be sure you are using good makeup water (I am sure you are already, but worth mentioning). As previously posted, the action of life will reduce PH by producing CO2 and good gas exchange will help with that. Did you mention you had plants? I use a algae turf scrubber timed to come on when the display tank light go off to counter PH swing caused by the day/night cycle. It has worked for 18 years and PH stays about 8.2.

Good luck with your rebuild. Tell dad to leave the power heads plugged in...

 

[Sebastian_Troy]

I did some sums on the rebuild and calculated that i couldn't afford it

Ok so I did a large water change obv, (using high quality makeup water ) and added kalkwasser to boost the KH calcium and pH, so now Calcium is above 500, KH is about 8 and pH is still about 7.7... If I add more buffer or Kalk I just get calcium snow in my tank however I need to to boost KH and pH still... What do I do?

 

[bavass]

you can buy a Alk additive and a PH up.

 

[RYANLAWRENCE]

Might try a pH booster other than kalkwasser

 

[Sebastian_Troy]

Can I use bicarbonate if soda instead? Funds are a little dry at the moment!!!

 

[Henry405]

The pH booster is prob less than $10 and it'll last you awhile.

 

[Sebastian_Troy]

Not in this tank it won't, not at this rate anyhow! Plus bicarbonate costs me £0 as I have a ton already for use in my dads pool. So would it work? I know it will ^ salinity and KH at the same time, but on it's own will it unbalance anything?

 

[Henry405]

i personally wouldn't use anything that would affect something else if pH is your only issue. If you use bicarbonate to raise pH, you'll then have to do water changes to lower the salinity.

the pH booster I have treats 1000g and it cost me $8

 

[Sebastian_Troy]

What are it's active ingredients?

 

[Sebastian_Troy]

Well I don't know but I know what a buffer is, it is a reversible reaction, which means under normal circumstances it is reacting and reacting back constantly, if it is reacting forward and backward at the same rate it's equilibrium leaves it at 50:50 half of the reactants and half the products, this equilibrium can shift from side to side up till 100% either way at which point it cannot react further, the equilibrium opposes change to it's environment, so it cancels out change in say pH (a pH buffer),

Anyway I Think the main point was that bicarbonate as part of a buffer is only one half of the equilibrium (possibly only one part of one half) and adding too much of one side of the equilibrium without the other can push it too far to the other side for it to act as a buffer anymore,
you may understand buffers better than me buy that's a pretty rough idea of buffers if you didn't know

 

[Sebastian_Troy]

Replied to the wrong thread, App Fail lol

 

[Feelthereefer]

Aim a power head at the surface for a while that should raise the ph with out chemicals you may not have enuff surface movement...when are you checking your ph that could have something with it as well

 

[Sebastian_Troy]

My water movement is definitely not the problem here, and I'm taking readings all the time, besides it's too low to just be a natural fluctuation!

 

[Feelthereefer]

Ohh..i dunno man be carefull using buffer u can drip in some kalkwas...i believe it has a ph of 13 or 12 either way your alk can come up some as well so I would give that a try and aim a power head at the surface lol...good luck