Phosphate free pH buffer

[njparton]

Is anyone aware of a PO4 free pH buffer available in the UK?

My RO water is <pH 4 and I need to raise it to 6.5. I have tried additives that increase GH but that is not sufficient and provides a 0.5 increase at most. I also need to raise KH.

I'm currently using Seachem's pH buffer powder, but it contains high levels of PO4 (removing PO4 from my tap water is one of the reasons I invested in an RO unit!).

I've tried to find some PO4 free baking soda, but have not been successful.

I'm currently using Kent R/O Right to raise GH.

I'd prefer to adjust the RO water pH to 6.5 prior to adding it to the tank to avoid pH fluctuations after a water change, I think this discounts adding some coral to my filter?

 

[Silly me]

maybe you could only R/O half the water?

 

[Tropjunky]

i alpays thought that RO water was suposesed to be PH7 as there were no inmuraties in it. well if only u has high PH then a co2 system would be the answer ( takes time though) and it'll be good 4 ur plants.

but i think u need to talk 2 ur LFS as they should know the product side of it a lot more than any of us.

 

[njparton]

maybe you could only R/O half the water?

That completely defeats the object and will leave me still with high PO4 levels.

 

[Bol]

Well, a 1/2-1/2 mixture doesn't defeat the object completely, but it may not, as you say, be sufficient.

I've tried to find some PO4 free baking soda, but have not been successful.

Are you sure you're looking at baking soda, and not baking powder? Most baking soda I've seen here in the US (such as Arm and Hammer) is merely sodium bicarbonate.

In any case, personally, the first thing I would look into is why your RO water has such an extremely low pH. That doesn't seem normal at all.

Also, and I may be wrong, from what I've learned GH has almost nothing to do with pH -- KH does, though. However, to maintain a pH of 6.5 under "normal" (i.e. no other buffers present, and no CO2 injection) conditions, your KH level would have to be pretty low.

 

[njparton]

From what I read in several places prior to the RO unit investment, RO water is always low in pH, so that's not completely unexpected. It's just harder to get back to neutral than I expected, like you say, because of the low KH.

I can't seem to find baking soda anywhere...

Would that alone be sufficient to raise the KH?

 

[Bol]

I don't have an RO unit, and I've heard that RO water can be low in pH, but usually the "low" mentioned in that case is around 6.0, ... below 4 is pretty darn acidic -- getting near orange juice or vinegar range. Of course, RO water should have almost no buffering ability at all, so maybe that's not unusual.

Seems odd that you can't find baking soda. It's usually found in groceries, in the "baking goods" section -- near the flours and such.


Baking soda itself is enough to raise your KH, and with it, your pH (assuming you don't have significant competing buffers in the water). Many people use it when using RO water. I've seen many different formulas for how much to add, but the one I trust the most is:

1 teaspoon of baking soda will raise the KH of 50L of water by 4 degrees (~ 72ppm). Generally, you want to keep a KH level of at least 3 degrees, for pH stability, but I'm not sure where that would put your pH.

And, just for info, I've found from a trusted source that the Seachem power buffer (Equilibrium) does use phosphates, and also raises your GH (as I'm sure you know), but Seachem also makes a liquid buffer (that I don't know the name of, sorry) that contains no phosphates and alters your KH, not GH.

 

[njparton]

I don't have an RO unit, and I've heard that RO water can be low in pH, but usually the "low" mentioned in that case is around 6.0, ... below 4 is pretty darn acidic -- getting near orange juice or vinegar range. Of course, RO water should have almost no buffering ability at all, so maybe that's not unusual.

Seems odd that you can't find baking soda. It's usually found in groceries, in the "baking goods" section -- near the flours and such.


Baking soda itself is enough to raise your KH, and with it, your pH (assuming you don't have significant competing buffers in the water). Many people use it when using RO water. I've seen many different formulas for how much to add, but the one I trust the most is:

1 teaspoon of baking soda will raise the KH of 50L of water by 4 degrees (~ 72ppm). Generally, you want to keep a KH level of at least 3 degrees, for pH stability, but I'm not sure where that would put your pH.

And, just for info, I've found from a trusted source that the Seachem power buffer (Equilibrium) does use phosphates, and also raises your GH (as I'm sure you know), but Seachem also makes a liquid buffer (that I don't know the name of, sorry) that contains no phosphates and alters your KH, not GH.

Thanks for the advice

I've found bicarbonate of soda (nothing else listed in ingredients) - is this what I'm looking for?


The Seachem powder I'm using is not called Equilibrium, and it does list PO4 as an ingredient.

It's strange, all my LFSs stock Kent and Seachem products, but not the ones I want! I'll have to speak to them...