HCO3- vs. CO2, baking soda an coral questionsz

[pejerrey]

I've been reading that aquatic plants use HCO3-(baking soda) as well as CO2. Some species have preferences.

I have not been using baking soda at all. My plants are doing well tho.

I think baking soda would raise the ph and make it more stable, truth?
This would be beneficial for some of my shrimp species that could use a bit more basic waters.

I would be bringing the ph up to 6.3ish from 5.5-5.6.

Is the use of baking soda ok with cardinias sp? I bet neos are ok.

I have some crushed coral to help the GH because that is what breeders use.it raises the KH a lil bit. Is this kind of the same? What does coral dissolve into the water column?

Can both things be used in conjunction or should I stick with one?

Thanks

Based on my understandings of page 3 "response of aquatic plants to abiotic factors-nutrients"
http://www.springerlink.com/content/g2k56p2083gr8057/fulltext.pdf?MUD=MP

 

[Tom Barr]

All aquatic plants, algae as well, prefer CO2, they only use HCO3 when there's not enough CO2 available.

We add baking soda most to be able to measure the CO2 with pH/KH, if you do not have any KH, then you cannot measure CO2 that way.
The equation becomes

pH = pK-log[CO2]/[HCO3] but if there's no valve in the denominator...........you cannot measure, the scale goes off the deep end.
You need some HCO3 to measure the CO2.

5.5-5.6 is typical for CO2 enriched low KH/absent. There's some other buffers in there, most tannins I'd suspect.
These modify and control pH and perhaps act as a buffer system with CO2.
No idea though, speculation based on observation.

 

[pejerrey]

It's the substrate. Akadama drl.

Should I even bother using baking soda?

To try to go from 5.6 to 6.5, is that a lot?

Does it stay stable or does it swing over time?

Is baking soda ok for cardinias?

What does coral dissolve into the water? Raises GH and KH.

Thanks

 

[Tom Barr]

Acclimation with KH change, salts, basically, if not the same as acclimation with say CO2. CO2 is not a salt.
So you need to go slow in that process, generally 1-2 hours of slow drip acclimation, even then............

For your tank/livestock I'd suggest this:

Take a cup of of water from the tank of known volume and do a test run. See how much baking soda is takes to get to 6.0. Then say 6.4.
Then measure TDS/Conductivity.

Compare that value with the optimal ranges for breeding CRS.
I'd say you have too low TDS. KH will be consumed by plants/bacteria also if the CO2 is too low.
So you'll need at it.

I'd also consider a Lamotte alkalinity test kit.
Measure it every month at least.

Baking soda should reduce swings in pH.
CaCO3 is coral, aragonite structurally.
Dolomite is much harder to dissolve, but it's got Mg Ca and CO3.
You can also use K2CO3 or KHCO3.Then use CaSO4 and MgSO4.

Up to you really.

 

[pejerrey]

Thank you!

Do you think I need to do this?
Probably not right?