Unstable PH

[nalah]

my tank water is at 6.5.
my aging water is at 6.5.
but ... i do wc and the next day,tank Ph drops to 5.5. WHY?

[chavez720]

What is the kH? This is a measure of the buffering capacity of the water. Below 3° and there will not be enough buffering to keep a steady pH and wild swings are possible.

[nalah]

Thanks Chavez,
i am still new to this hobby.
so far,i am keeping my fish healthy and alive.now,i have to learn more about their water.
still a bit confused about the term " buffering"
???

[chavez720]

Capacity of a system to resist change. With water this is usually accomplished by a Carbonic acid (HCO3)/ Carbonate(CO3) system (weak acid/weak base). The carbonate can be measured in °kH. Lower the kH the less resistance the water has to changes in pH. Not enough buffering (°kH) is why pH crashes happen - fish respire adding CO2, decomposition of detritus, other metabolic processes, etc etc - usually resulting in an extremely low pH.

Other system of interest are humic acid (from peat) and phosphate systems.

[Denny]

are you you using an airstone or anything in your holding container? usually after doing this(your aq. filter does the same thing).the ph rises as co2 is driven off. you may have very low carbonate hardness which can lead to unstable p.h in the tank. do you know what the gh and kh values are? it may end up that you need to add crushed coral or limestone to bring up the kh.


denny

[fcdiscus]

Try about a 1/4 tsp of baking soda in your set up water. Frank

[nalah]

tap PH is unstable lately. last week was around 8.5,today,its 7.5.
(sydney dams are very low due to draught season.... maybe that affects it.??)

Tap - 50ppm (2.8dH)/ ph 7.5

Holding - 50ppm / ph 7.0 (here i use prime and was using acid buffer)

Tanks - 50ppm / 2 tanks on 5.5ph, one tank on 6.0ph

in the holding tank,i am running underwater filter with carbon only in it.

you say that ph rises after aeration...mine drops

[jsojda]

I dont mean to steal the thread Pascale but i beleive that i have a similar problem. My KH is 3 and my GH is 7-8. I was curious as to the effects that baking soda would have on my ph and conductivity. I have heard that in addition to rasing the KH my ph and conductivty would be increased as well. Any ideas?

[chavez720]

Pascale - Is there alot of Sodium (Na) in your water? Sounds as though there is something else buffering your system - phosphate, humic acid (peat). Na will also affect the the Ca/Mg (GH) balance. Is there any way that your water is flowing through a softener - these replace Ca/Mg with Na. Seems a though your kH and Gh readings are good and you should not have a problem with keeping pH stable. Na will somewhat affect your Gh reading - read high when it is not.

[nalah]

Chavez
I dont have an Na tester.. should i get one??
i am not using peat or similar.
today i am doing wc. but tested water in tanks...dropped down further to around 5.5.
really dont know whats going on.

i have only put Prime in stored water. so ph there is much higher than in tanks...
what do i do? lower ph of stored water or raise ph in tanks.

[Carol_Roberts]

It seems like one of the water conditioners lowers pH - maybe it was Prime? REad label or instruction sheet.
Carol :heart1:

[chavez720]

What is prime - never heard of this water conditioner? Does it contain salts - mg, ca, carbonate?

Do not think they make an inexpensive Na tester - refractometer $150US. Could check conductivity - High conductance high salt concentration. This will measure total ions not just Na.

Do what frank said. Add 1/4 tsp per 10 gallons and see if that holds your ph up for a day or two. You may not have enough alkilinity in the tank.

Brad

[nalah]

Carol.
Prime does not alter ph... or so it says on the bottle.
i have not lowered ph in my holding drum. i will test tank again today and see results.

baking soda - in the drum or straight in tanks??