A Different Co2 Theory

[jimbooo]

okay that makes perfect sence. thanks for the feedback Aku.

 

[Nim]

Think I missed this thread as I am not really active on this forum..

The reason I got into this experiment was because my pressurized CO2 ran out and I am still having trouble finding a fish store that fills Bioplast cylinders in the UK ... anyways.

Back in March of 2005 I setup a Juwel Rio 240 tank with Flourite and Heating cable with 2x 70W Halides (5200K RX7s Bulbs) and a Grolux 40W (Since the 5200k halides lack a bit of pink and red for aesthetic reasons).

I had a spraybar running at 45 degrees to the water surface at 1/2" above water. The plants were as below:
Various Crypts,
Limnophilla aquatica
Hygrophylla difformis
Hydrocotyle leuceopholia (sorry cant spell the second part)
Hygro polysperma
Java Moss & Ferns
Water sprite
Amazon swords
Valliseneria
Echinodorous Rose (very very large)
Echinodorous red ozelot
Ludwigia repens
Couple of mayaca fluvitalis
Red Myriophyllum
I had the tank running like this for about 3 months. Heavy fish load (about 1.5" of fish per gallon) and the plant growth was phenominal. The only plants that suffered hard were Amazon swords and water sprite (Indian Fern). I did have some trouble with Hair algae initially but when I increased the dosage of Flouroish to about a capfull once every 3 days, things started to come under control.. hair algae still remained but only in the Java moss that was eventually fed to my mbunas later.

On the 3rd month I decided to check by turning off surface agitation.. Below is what happened within 1 week of pushing the spraybar below the water surface:

Hydrocotyle, Myriophyllum, Limnophilla, Echinodorous ozelot, mayaca fluvitalis (it was not doing very well as it is) and a couple of crypts perished. I could not recover them even after re-applying pressurized CO2 (~25ppm) back on the tank... Amazon sword was already almost lost with the halides.

The basic Idea was:
at upto 2.5WPG of lighting, surface agitation and airstone can help to prevent CO2 starvation on plants which is the main reason why people have difficulties growing plants when they dont have any CO2 injection methods..We used to always stress very strongly on "DO not use any syrface agitation" even when someone did not have any CO2 injection... why? When there is almost nothing in the water that is providing any CO2 to the plants, why prevent surface agitation from getting atmospheric CO2 dissolved in the water?

Agreed that surface agitation will drive off CO2 from the water but this CO2 is in literal terms the EXCESS of CO2. Water will still be able to hol;d low amounts of CO2.. ofcourse not in 20 or 30PPM because the PPM measurements of CO2 is based on an un-natural system as it is from scratch and does not exist in nature.

What we are doing is providing plants with a constant supply of CO2 all the time though its is not a CO2 enriched enviornment but it is also not a CO2 deficient enviornment.

Below is a link to the tank setup. I did start with pressurized CO2 and it is most obviously better then the surface agitation theory but the surface agitation is much better then no CO2 injection.

http/www.nimmat.com/coppermine/displayim...?album=19&pos=3

The newer pics are of the tank without halides but 3x 38W T8s (Triplus, Arcadia freshwater & Grolux). Tetra Complete substrate as the underlayer and a good level of surface agitation created by the Juwel internal filter and ofcourse no CO2 injection.
Most of the plants are polysperma, crypts and limnophylla but at themoment I even have some lillaeopsis and hydrocotyle in there thats doing well.

I have setup another tank with a single 70W halide over a 28 gallon tank and an eheim HOT filter and a spray bar doing the work again I call them Natural systems

Discussions welcome.

Nim

 

[iggy01]

On the 3rd month I decided to check by turning off surface agitation.. Below is what happened within 1 week of pushing the spraybar below the water surface:

Hydrocotyle, Myriophyllum, Limnophilla, Echinodorous ozelot, mayaca fluvitalis (it was not doing very well as it is) and a couple of crypts perished. I could not recover them even after re-applying pressurized CO2 (~25ppm) back on the tank... Amazon sword was already almost lost with the halides.

I'm not surprised you had success using this method.

As you stated, creating surface agitation ensures a constant level of CO2. By ceasing the agitation, you stopped the constant supply of CO2 for the plants. Chances are, the plants would begin to run out of CO2 several hours after lights on. Therefore CO2 becomes the limiting factor.

It baffles me why people advise minimal surface agitation in non CO2 injected tanks. In fact, it even puzzles me why people with pressurized systems also have very little surface movement. I'm not suggesting having an airstone running 24/7, but having a certain amount of surface movement helps with O2 levels also.

 

[Nim]

It baffles me why people advise minimal surface agitation in non CO2 injected tanks. In fact, it even puzzles me why people with pressurized systems also have very little surface movement. I'm not suggesting having an airstone running 24/7, but having a certain amount of surface movement helps with O2 levels also.

People having pressurized systems will infact lose the CO2 they are pushing in if they have surface movement. Any surface movement drives off any EXCESS gasses that have been dissolved in the water which includes injected CO2 and also includes the Oxygen produced by the plants during pearling. Pearling means the water is saturated of O2 and having any surface movement really reduces the amount of oxygen in the water from a saturated enviornment.

But yes, if one does not have any CO2 injection, there is no point trying to minimize surface movement or prevent gasseous exchange as there is really nothing that the gaseous exchange will drive off from the water.

I hope it makes a bit of sense

 

[George Farmer]

That makes perfect sense Nim. Thanks for explaining.

 

[iggy01]

It baffles me why people advise minimal surface agitation in non CO2 injected tanks. In fact, it even puzzles me why people with pressurized systems also have very little surface movement. I'm not suggesting having an airstone running 24/7, but having a certain amount of surface movement helps with O2 levels also.

People having pressurized systems will infact lose the CO2 they are pushing in if they have surface movement. Any surface movement drives off any EXCESS gasses that have been dissolved in the water which includes injected CO2 and also includes the Oxygen produced by the plants during pearling. Pearling means the water is saturated of O2 and having any surface movement really reduces the amount of oxygen in the water from a saturated enviornment.

But yes, if one does not have any CO2 injection, there is no point trying to minimize surface movement or prevent gasseous exchange as there is really nothing that the gaseous exchange will drive off from the water.

I hope it makes a bit of sense

Yes, I understand that.

The point I was trying to make, is some people have virtually no movement whatsoever. Pearling is fine for during the day, but at night the situation changes. Some run CO2 24/7. Plants don't pearl at night and O2 levels can be used up by morning.

I always ensure adequate surface movement and my plants pearl fine. It may cost a little extra in CO2, but not much.

 

[George Farmer]

One thing I have realised is that water movement and surface agitation are different. Plants like plenty of movement as it transports nutrients effectively. If this can be achevied with minimal surface agitation, and therefore less CO2 loss through surface agitation, then all the better.