Chaeto not growing

[LMSquire]

Hey all,

IM 240 DT w 75 sump. Mixed reef.

The chamber that I have my Refugium in has light running 24/7 and the chaeto ball spins with a gyre.

For whatever reason the ball does not seem to grow.

Any advice? Parameters are as follows:

 

[Tangdora]

What spectrum of light are you running. Should also run your light at 16 hours max giving at least 8 hours of rest.

 

[LMSquire]

What spectrum of light are you running. Should also run your light at 16 hours max giving at least 8 hours of rest.

Idk the spectrum, it’s the IM refugium light, it’s a pink/purple color.

I’ll turn it down to 16 hours, thanks!

 

[atlantean]

I'd double check your nitrate and phosphate with another kit or calibrate your Trident. If my chaeto stops growing I know they are getting low in my tank.

 

[Subsea]

Seaweed requires both major and minor nutrients.

Know this, seaweed is not controlled by the the most abundant nutrient but it will be limited by the least. Check your trace minerals, particularly iron & silicates. Many use chaetogrow, I use concentrated kelp fertilizer and ammonia.

 

[EnterName]

Short answer:
There are very likely trace elements missing which are absolutely necessary for algae growth. Note that ICP-OES might not suffice as for example iron won't be detected in natural seawater concentrations so you will need an ICP-MS test if you want to check for deficiencies.


Details:
Nitrate and nitrite cannot be used directly by algae (or corals), so they get converted back to ammonium with enzymes. This is also the reason why some people dose ammonium instead of nitrate to nitrogen-deficient systems as it can be used more directly.

The required enzymes (see nitrate/nitrite reductase) use molybdenum and iron. If one of those elements isn't available the nitrogen uptake and therefore growth will stall.

A few examples for additionally required trace elements:
- Nickel for urea consumption (see urease enzymes)
- Zinc for inorganic carbon supply (see carbonic anhydrase enzymes)
- Copper for photosynthesis (see plasticyanin)
- Manganese for photosynthesis (see oxygen-evolving complex)
- Cobalt for Vitamin B12 uptake and synthesis


The challenge:
Unfortunately we can't really measure trace elements at home with sufficient precision. This means we have to either spend a lot of money on frequent ICP-MS tests, or we have to know the trace element demand of our system well enough to compensate blindly for longer periods of time. There are many options available for adding trace elements ranging from adding a single solution containing everything to adding each trace element individually.

 

[Subsea]

Short answer:
There are very likely trace elements missing which are absolutely necessary for algae growth. Note that ICP-OES might not suffice as for example iron won't be detected in natural seawater concentrations so you will need an ICP-MS test if you want to check for deficiencies.


Details:
Nitrate and nitrite cannot be used directly by algae (or corals), so they get converted back to ammonium with enzymes. This is also the reason why some people dose ammonium instead of nitrate to nitrogen-deficient systems as it can be used more directly.

The required enzymes (see nitrate/nitrite reductase) use molybdenum and iron. If one of those elements isn't available the nitrogen uptake and therefore growth will stall.

A few examples for additionally required trace elements:
- Nickel for urea consumption (see urease enzymes)
- Zinc for inorganic carbon supply (see carbonic anhydrase enzymes)
- Copper for photosynthesis (see plasticyanin)
- Manganese for photosynthesis (see oxygen-evolving complex)
- Cobalt for Vitamin B12 uptake and synthesis


The challenge:
Unfortunately we can't really measure trace elements at home with sufficient precision. This means we have to either spend a lot of money on frequent ICP-MS tests, or we have to know the trace element demand of our system well enough to compensate blindly for longer periods of time. There are many options available for adding trace elements ranging from adding a single solution containing everything to adding each trace element individually.

Kudos to your post. Outstanding overview of a complex subject.

“Refugium in has light running 24/7 and the chaeto ball spins with a gyre.“

@LMSquire

While I have grown Chaetomorphy in rugiums for nutrient export, I did not find it an optimum choice. With respect to tumbling a ball of chaetomorphy, as a growout facility, I prefer tumbling seaweed that does not clump up like spaghetti.

Consider a different seaweed like Gracilaria Hayi or Ulva. They tumble much better with less energy required. I use long narrow rectangle tanks with a vertical loop current.

 

[Subsea]

“The required enzymes (see nitrate/nitrite reductase) use molybdenum and iron. If one of those elements isn't available the nitrogen uptake and therefore growth will stall.”

“A few examples for additionally required trace elements:
- Nickel for urea consumption (see urease enzymes)
- Zinc for inorganic carbon supply (see carbonic anhydrase enzymes)
- Copper for photosynthesis (see plasticyanin)
- Manganese for photosynthesis (see oxygen-evolving complex)
- Cobalt for Vitamin B12 uptake and synthesis“

@EnterName
I found this information very detailed. Thank you.
Are you a phycologist?

 

[EnterName]

“The required enzymes (see nitrate/nitrite reductase) use molybdenum and iron. If one of those elements isn't available the nitrogen uptake and therefore growth will stall.”

“A few examples for additionally required trace elements:
- Nickel for urea consumption (see urease enzymes)
- Zinc for inorganic carbon supply (see carbonic anhydrase enzymes)
- Copper for photosynthesis (see plasticyanin)
- Manganese for photosynthesis (see oxygen-evolving complex)
- Cobalt for Vitamin B12 uptake and synthesis“

@EnterName
I found this information very detailed. Thank you.
Are you a phycologist?

Nope not a phycologist, biologist, chemist or anything related. Just a nerd trying to learn and make sense of all this stuff going on in my reef tank. I have a degree in computer science and rely on reading through articles, scientific papers, etc. From time to time I misunderstand things, but I'm giving my best to provide informed advice.

I'm teaching myself some chemistry and love microscopy, so I just read a lot about all this stuff, but when someone with an actual degree comes around and disagrees with what I say, you are better off listening to them than to me.

 

[mcarroll]

Hey all,

IM 240 DT w 75 sump. Mixed reef.

The chamber that I have my Refugium in has light running 24/7 and the chaeto ball spins with a gyre.

For whatever reason the ball does not seem to grow.

Is this a reef or coral tank, or something else??

A consideration that most folks seem skip over – maybe your tank doesn't need (or want) to grow macro algae and you can just focus on your reef! :)

Growing macro algae is really a tool for high-nutrient systems that have a problem with persistently high nutrients. If that doesn't describe your tank, then it seems like you might just be making work and worrying about something that doesn't even matter.

 

[LMSquire]

I'd double check your nitrate and phosphate with another kit or calibrate your Trident. If my chaeto stops growing I know they are getting low in my tank.

I do it about every two weeks but I’ll calibrate with Hanna tomorrow

Short answer:
There are very likely trace elements missing which are absolutely necessary for algae growth. Note that ICP-OES might not suffice as for example iron won't be detected in natural seawater concentrations so you will need an ICP-MS test if you want to check for deficiencies.


Details:
Nitrate and nitrite cannot be used directly by algae (or corals), so they get converted back to ammonium with enzymes. This is also the reason why some people dose ammonium instead of nitrate to nitrogen-deficient systems as it can be used more directly.

The required enzymes (see nitrate/nitrite reductase) use molybdenum and iron. If one of those elements isn't available the nitrogen uptake and therefore growth will stall.

A few examples for additionally required trace elements:
- Nickel for urea consumption (see urease enzymes)
- Zinc for inorganic carbon supply (see carbonic anhydrase enzymes)
- Copper for photosynthesis (see plasticyanin)
- Manganese for photosynthesis (see oxygen-evolving complex)
- Cobalt for Vitamin B12 uptake and synthesis


The challenge:
Unfortunately we can't really measure trace elements at home with sufficient precision. This means we have to either spend a lot of money on frequent ICP-MS tests, or we have to know the trace element demand of our system well enough to compensate blindly for longer periods of time. There are many options available for adding trace elements ranging from adding a single solution containing everything to adding each trace element individually.

thanks so much for the thorough answer!

 

[LMSquire]

Is this a reef or coral tank, or something else??

A consideration that most folks seem skip over – maybe your tank doesn't need (or want) to grow macro algae and you can just focus on your reef! :)

Growing macro algae is really a tool for high-nutrient systems that have a problem with persistently high nutrients. If that doesn't describe your tank, then it seems like you might just be making work and worrying about something that doesn't even matter.

It is a mixed reef, exactly one year old. I am growing the macro algae in order to help export the po4 in my tank which is too high for my liking at 0.1…I have some acro going and I don’t think they like it. At one year my coralline growth has been pretty impressive, see photo below.