Does cheato use Ca/Alk/Mg ?

[holdyourlight]

Does chaeto need anything besides light, nitrates, phosphates, iron/micros to grow?

For example, lets take a system with no corals and a calcium level of 200, dkh is 5 and mag is 900. ( These are not my actual levels, though they might be, I haven't tested my fowlr in years).

 

[Brew12]

It may use a little mag, not sure about that. Chaeto does not use appreciable amounts of calc or alk.

 

[Randy Holmes-Farley]

Your levels are not low due to chaeto.

It uses many elements, but you will not be able to detect the small amounts of calcium and magnesium it consumes relative to the large amounts in seawater. The depletion of elements such as iron, which are present at very, very much lower concentration in seawater to begin with, can be substantial.

It does not "use" alkalinity, bit if it consumes nitrate (something we often to not have a good understanding of, relative to consuming, for example, ammonia), it provides alkalinity in the exact amount that the formation of that nitrate from ammonia depleted it. If you are doing nitrate, you might see an alk rise from taht effect.

 

[holdyourlight]

Thanks Randy.

I didnt suspect chaeto was causing my low levels. I wanted to make sure that chaeto could grow in a system that already has very depleted levels of cal, alk and mag, where none of these will be supplemented and water changes will be basically never. Iron + micros will be dosed though...

Your levels are not low due to chaeto.

It uses many elements, but you will not be able to detect the small amounts of calcium and magnesium it consumes relative to the large amounts in seawater. The depletion of elements such as iron, which are present at very, very much lower concentration in seawater to begin with, can be substantial.

It does not "use" alkalinity, bit if it consumes nitrate (something we often to not have a good understanding of, relative to consuming, for example, ammonia), it provides alkalinity in the exact amount that the formation of that nitrate from ammonia depleted it. If you are doing nitrate, you might see an alk rise from taht effect.

 

[Randy Holmes-Farley]

Thanks Randy.

I didnt suspect chaeto was causing my low levels. I wanted to make sure that chaeto could grow in a system that already has very depleted levels of cal, alk and mag, where none of these will be supplemented and water changes will be basically never. Iron + micros will be dosed though...

lol

That's a different question. Sorry, I interpreted the original question wrongly.

Chaeto doesn't "consume" alkalinity, but many macroalgae use bicarbonate as their source of CO2, so they may "need" alkalinity in the water. I add baking soda if you want it to thrive optimally. The chaeto returns the alk to the water (by taking up H+ most likely) so there is no loss of alk, just a loss of bicarbonate.

I'm not sure how important calcium and magnesium in the water may be, but I also would not assume it is negligeable. All photosynthetic organisms need some calcium from the water, and may have a harder time getting it at less than half the normal concentration. Less sure on the magnesium.

 

[holdyourlight]

Thanks

So how do I figure out how much baking soda to add if the alk number doesnt change?

lol

That's a different question. Sorry, I interpreted the original question wrongly.

Chaeto doesn't "consume" alkalinity, but many macroalgae use bicarbonate as their source of CO2, so they may "need" alkalinity in the water. I add baking soda if you want it to thrive optimally. The chaeto returns the alk to the water (by taking up H+ most likely) so there is no loss of alk, just a loss of bicarbonate.

I'm not sure how important calcium and magnesium in the water may be, but I also would not assume it is negligeable. All photosynthetic organisms need some calcium from the water, and may have a harder time getting it at less than half the normal concentration. Less sure on the magnesium.

 

[the weird one]

Thanks

So how do I figure out how much baking soda to add if the alk number doesnt change?

If you stop seeing their pearling ( photosynthesis) after a few hours of light you know you have to add baking soda. There might be a certain cycle and you can dose the amount of baking soda you think would be appropriate after a certain days to keep them pearling everyday.

 

[Dan_P]

Does chaeto need anything besides light, nitrates, phosphates, iron/micros to grow?

For example, lets take a system with no corals and a calcium level of 200, dkh is 5 and mag is 900. ( These are not my actual levels, though they might be, I haven't tested my fowlr in years).

You have the basics. Macro algae can self shade as they grow larger so water movement is important to keep exposing the entire plant to light by having it tumble. In general water, circulation is needed to bring in nutrients and remove waste quickly. When flow is inadequate, slime may start to accumulate on the algae.

 

[Randy Holmes-Farley]

If you stop seeing their pearling ( photosynthesis) after a few hours of light you know you have to add baking soda. There might be a certain cycle and you can dose the amount of baking soda you think would be appropriate after a certain days to keep them pearling everyday.

I have no idea what you are referring to, but I definitely do not recommend that folks try to gauge a need for alkalinity based on some visual appearance of photosynthesis.

Alkalinity need is easily determined with an alkalinity test kit.

 

[the weird one]

I have no idea what you are referring to, but I definitely do not recommend that folks try to gauge a need for alkalinity based on some visual appearance of photosynthesis.

Alkalinity need is easily determined with an alkalinity test kit.

That's reasonable. Maybe i shouldn't have made such big statement. Using test kit must be safer.

It's just simply base on my experience that i'm still using. My caulerpa lentillifera, stop growing everytime they stop "pearling" having that oxygen bubble on their branch. I found that they pearling the strongest after a water change or a few hours after i dose baking soda and they will stop pearling a few day after that. So they must using something from the water or baking soda. I figure out the time cycle is around 3 to 4 day for my tank, so i raise KH 1 dkh every two days to counter that. And my macro algae keep growing well. Still nothing has died yet in my tank so i gave him the advise but doing the test probably would be much safer when it come to dosing stuff into your tank. Thank you Randy.

(sorry my english is horrible)

 

[the weird one]

I have no idea what you are referring to, but I definitely do not recommend that folks try to gauge a need for alkalinity based on some visual appearance of photosynthesis.

Alkalinity need is easily determined with an alkalinity test kit.

beside i was answering to this question of him :

Thanks

So how do I figure out how much baking soda to add if the alk number doesnt change?

As you said, the alkalinity doesn't change but the macro algae still use up the bicarbonate. So even when the bicarbonate depleted the alkalinity test won't show anything. That's why i gave that answer, the test doesn't show then isn't visual sign is the only way to know when to dose baking soda for macro algae? I think there was a misunderstanding here.

 

[Randy Holmes-Farley]

That's reasonable. Maybe i shouldn't have made such big statement. Using test kit must be safer.

It's just simply base on my experience that i'm still using. My caulerpa lentillifera, stop growing everytime they stop "pearling" having that oxygen bubble on their branch. I found that they pearling the strongest after a water change or a few hours after i dose baking soda and they will stop pearling a few day after that. So they must using something from the water or baking soda. I figure out the time cycle is around 3 to 4 day for my tank, so i raise KH 1 dkh every two days to counter that. And my macro algae keep growing well. Still nothing has died yet in my tank so i gave him the advise but doing the test probably would be much safer when it come to dosing stuff into your tank. Thank you Randy.

(sorry my english is horrible)

What you may be observing is a pH effect, not an alkalinity effect.

There are two possibilities that could explain an observation like yours.

Some macroalgae use CO2 directly, and thus they may photosynthesize more slowly at higher pH. Adding bicarbonate will lower the pH a small amount.

Many macroalgae use bicarbonate for CO2. They release OH- to convert it to CO2, and that raises pH. If the tank is not sufficiently aerated, that effect may raise pH significantly and the effect is less bicarbonate and more carbonate. Thus, adding more bicarbonate will possibly allow a lower pH/higher alk which can help increase photosynthesis.

I caution that folks should monitor alk by testing, and it may be better to offset these effects through other means, such as aeration.