[Mr_Bubbles]

Hey Everyone,

I posted a similar post on another forum but wanted to ask this here too since I thought I might get more response.

I read that co2 uptake is affected by how much no3/po4 is in the tank. So I'm wondering, I've been dosing a little higher then what is listed in the EI sticky, and have felt that my co2 levels may be too low for what the plants need. If I drop these back down to those levels, will this mean I won't have to push my co2 so hard, to get healthy growth and find balance? I was under the impression excess nutrients just made them less limiting and didn't realize there was an actual balance between co2 and those nutrients (I thought co2 balance was more related to light, though i did know not having enough no3/po4 would have an effect on co2 uptake, but was unaware that having more excess would require more co2). If this is in fact the case, I think I better change my dosing regiment back to what has been listed. Anyone know if this is true?

Thanks!

 

[Optix]

1. fix nutrients
EI so youre good

2. control CO2

if youre low on CO2, thats your limiting factor...either up CO2 or lower your lighting

3. enjoy your tank


the simplified answer to your question is...when a plant depletes whatever nutrient (CO2, nitrogen, calcium, potassium etc), complete/proper/ideal photosynthesis stops ...and you get deformed plants

so if you had A LOT of CO2 and no nitrogen, the plant shuts down...giving algae a chance to move in
but if you keep the plant happy (with nutrients in excess, and light in moderation)...the plant will be photosynthesizing until the lights turn off (never giving algae a chance to take over, though it is always there)

it took me a while to [STRIKE]understand[/STRIKE] accept this point

but it really is that simple

 

[Hoppy]

Light intensity drives plant growth rates. The higher the intensity the faster the growth rate. But, that is only if the plants get the nutrients needed to build the new plant tissue. So, the goal should be to choose a light intensity that will give the growth rate you desire, then dose enough of every needed nutrient, including CO2, so the plants never experience a shortage of any nutrient. If you dose too little nitrates, for example, the most aggressive plants will use up all of the nitrates, to the detriment of the slower growing plants, and algae will take advantage of the unhealthy plants and begin growing. Since not all of the plants will be growing well, the other nutrients will not be as much in demand, so you could say that you don't need as much of them. But, remember, the consequence of this scenario is lots of algae problems.

 

[Mr_Bubbles]

ok, so provided i have enough co2 for good plant growth, it won't make a difference how much no3/po4 i dose, as long as it's not limited and not toxic to fish?

EI recommends 3/4 tsp kno3 and 1/8 tsp kh2po4 for my tank, but i've been dosing 1 1/4 kno3 and 1/4 kh2po4, i was worried that by dosing more, in order to keep balance and avoid algae issues, i would need to bump my co2 up higher then if i was dosing the standard EI dosing. So, is this incorrect?

 

[Optix]

yes, that is incorrect

Light is the gas pedal -controls the speed of growth in the plants

Nutrients are the fuel -without fuel, your car wont move regardless how hard you hit the gas pedal

CO2 are the tires -if you have a flat tire (insufficent CO2), you can only drive so fast safely (adjust light intensity depending on pressurized CO2/DIY CO2)

 

[Mr_Bubbles]

ok great, good to know, thank you!