Sodium bicarbonate vs sodium carbonate

[Reef Pilot]

Any opinions and experience about which is better? In the past have used sodium carbonate (from Seachem), but in the last year have gone to the much cheaper bulk bicarbonate. My SPS growth has not been as fast lately (but there may have been other reasons).

I have not tested my pH for a long time,... maybe I should. Does higher (and consistent pH) make a difference to SPS? The carbonate is supposed to be better to maintain a higher pH.

[Myka]

Some people find benefit to switch to carbonate during the winter when low pH can be a problem. Most tanks do just fine with bicarbonate. I haven't used carbonate for many, many years. If you test pH use a calibrated pH meter.

[Reef Pilot]

Originally Posted by Myka

Some people find benefit to switch to carbonate during the winter when low pH can be a problem. Most tanks do just fine with bicarbonate. I haven't used carbonate for many, many years. If you test pH use a calibrated pH meter.

Does lower pH affect SPS growth?

[Myka]

Originally Posted by Reef Pilot

Does lower pH affect SPS growth?

If it's low enough (or high enough for that matter).

[Reef Pilot]

Originally Posted by Myka

If it's low enough (or high enough for that matter).

I am sure my pH varies from day to night time. What range do you consider good for SPS? Or conversely, what pH is bad for SPS?

[Animal-Chin]

I dose carbonate that I buy in powder form at J&L and mix myself. I use dosing pumps that come on once an hour and my ph stays at a steady 8.2. I stopped testing it years ago though cause I found that if you keep your alk in check your PH will stay stable, at least in my tank it does.

For coral growth I've found alk and calcium levels are more important than chasing ph. Aim for stability and your system will run right unless you maintain a stable number that is way off the charts or something like that.

I've heard claims like "SPS need alk of 12" or "PH has to be 8.4" over the years but I run a very successful sps system with my alk at 7.8 - 8.

I really don't think there are perfect numbers, only acceptable ranges for all reef tank numbers.

Ok, I've rambled enough...lol

[Myka]

Originally Posted by Reef Pilot

I am sure my pH varies from day to night time. What range do you consider good for SPS? Or conversely, what pH is bad for SPS?

It probably does. Most SPS tanks will start to suffer below 7.8 and above 8.4. Ideally, you want to be around 8.2-8.3, but as Chin says, don't chase the pH too much. Remember that pH is a result of several factors. It's like baking a cake...err...it's like a carburetor, you gotta get the mix right or it doesn't run properly. The "mix" primarily being CO2 and oxygen - though the source of CO2 (causing acidification, or lowering of pH) isn't always obvious.