CO2 with "carbon rich" substrates?

[chkltcow]

In my 20g guppy tank, I have Onyx Sand and Flourite as the substrate, and both say they're carbonate rich plant substrates. Right now I have lilaeopsis, water sprite, and dwarf sag in there and they all seem to be doing okay, just interior sections of the VERY dense lilaeopsis bundles turning yellow and dying. As I plant more and more in this tank, will I have to do CO2 injection, even with these "carbon rich" substrates, or will they provide all the carbon necessary?

Re-reading this, I know it sounds dumb, but I'm a bit leary about doing a DIY CO2 rig in a tank this size and overdoing it.... and at the same time I don't want to spend the money on one of those super expensive kits either.

 

[Silly me]

more and more and more plant wouldnt use more CO2 if there is not an increase in light aswell.. CO2 get into the tank the same way as O2 its just that with 3+ wpg you might need to add more as the rate of growth increase.. if the plant growth = the CO2 currently in the water ??

aslo not all nutrience can be absorb from the substrate.

 

[abstract]

You can get the Hagen system for only 20 or 30 dollars!

 

[BuntbarschXXL]

You can get the Hagen system for only 20 or 30 dollars!

Is it the Nutrafin BioCO2 system?

If yes, you can build it yourself. Costs: Some dollars.

 

[Lateral Line]

I'm suprised speciality tank substrates would be carbonate rich actually. Carbonates harden water and raise it's pH. Generally, the only freshwater set up that should use carbonate substrates is a rift valley system.

Anyway, having carbonates in the tank is not the same as injecting CO2. Lilaeopsis species are all somewhat difficult to grow. They need strong light and CO2 to really thrive.

 

[chkltcow]

Is there an alternative to CO2 injection? Would Flourish Excel provide the necessary carbon?

 

[Lateral Line]

The only "additive" I've ever seen that adds CO2 was some highly dubious tablets which contain both an acid and carbonate. Added to the tank, the acid reacts with the carbonate and produces CO2 bubbles. I wouldn't trust them mind.

 

[fraservet]

tablets can work, but end up very expensive

if I ever add CO2 to my tank, I will probably get the electric plate thing (can't think of correct name at the moment), which passes a current across metal plates, producing CO2.
the advantages of this are - easily adjustable, no gas cannister, switch on/off at will.

does anyone have any experience of these?

 

[Lateral Line]

>>> the electric plate thing

Never heard of that. How does it work? Normally, an electrolysis cell produces Hydrogen and Oxygen, not CO2. I can't see the source of the raw materials.

 

[Yeaulman]

I think they are talking about this:Electric CO2 system

 

[Colin_BC]

Is there an alternative to CO2 injection?  Would Flourish Excel provide the necessary carbon?

Sorry if I'm way off here, but I think you have the wrong idea of what "CO2" is. CO2 is not actually Carbonate. CO2 is carbon dioxide which is a gas that plants "breathe in" to aid in photosynthesis. No liquid plant supplement should contain CO2. As Silly Me stated, CO2 get into the tank the same way as oxygen (disolves into the water through natural exchange). Unless your lighting is quite high, additional carbon dioxide probably isn't needed in your tank.

I'm surprised no one else has asked this yet, but I'd be happy to toss it out. What sort of lighting do you have above your tank and at what wattage? If the lighting isn't adequate than your money and efforts may be wasted on such things as good quality substrate, plant supplements, and carbon dioxide.

fraservet Posted on Aug 30 2004, 09:39 AM
  tablets can work, but end up very expensive

if I ever add CO2 to my tank, I will probably get the electric plate thing (can't think of correct name at the moment), which passes a current across metal plates, producing CO2.
the advantages of this are - easily adjustable, no gas cannister, switch on/off at will.

does anyone have any experience of these?

Personally, i'd consider the tablets to be a collosal waste. For what it would cost for even 1 month's worth, you are far better off (and cheaper) to buy a Nutrafin Natural CO2 system plus it comes with a 3 months supply of activator and stabilizer pouches. I use one in my 30G with 4WPG and a jungle of plants with no regrets. That electric unit is interesting, but I wonder how long each carbon block would last. At $120 USD (and that's with a $36 savings from regular price...) for the initial unit and $37 USD for each refill block, I think I would still stick with my Nutrafin system...

Colin

 

[chkltcow]

I have a basic understanding of plants and CO2, I think. Plants need carbon, and that usually comes in the form of CO2. They take in CO2, use the carbon, and convert it to O2 through photosynthesis. They can use carbon from other sources but it's not gonna result in "pearling." I had looked at Flourish Excel and it says it contains usable organic carbon, so I was wondering if their substrates were also usable carbon. I was just questioning if they can use the carbon from other sources such as the substrate itself.

As for plants I have, I'm still waiting on the big order I placed, but right now I have some lilaeopsis, dwarf sag, and water sprite in it... a 20g long with 55 watts overhead from 2 24" flourescent tubes and an 18" flourescent tube. The water sprite is growing fast, the dwarf sag is doing oky, and the lilaeopsis is dying in the thick bunched up sections but sending off runniers, so I'm assuming it's doing okay as well. When talking about the wattage, keep in mind that the water itself is only about 10" deep from the surface to the substrate, due to a thick layer of substrate, and a shallow tank.

The water chemistry (as far as plants are concerned) is:

pH 7.2
dKH 6
dGH 8-9

 

[Lateral Line]

>>> I think they are talking about this

Hmmm, never seen one of those, I can see where the raw material comes from now though, you have to supply it.

When CO2 gas dissolves in water it forms a weak acid, Carbonic acid, H2CO3. This dissociates into a Hydrogen ion and a Bicarbonate ion. Bicarbonates are soluable in water to a vastly greater extent then Carbonate ions. The metabolic pathways used for binding CO2 in aquatic plants are geared to Bicarbonate processing since that is the greatest source of available Carbon. Small amounts of carbonates are used by plants, but the majority of their CO2 requirement comes from dissolved CO2 gas.