Macro was thriving then started dying

[Kelliwilliams817]

My LFS has been desperate for chaeto and when he heard I had a spare tank laying around (50 gallon lowboy) he suggested I try my hand at growing some to sell him.

I started with a fist sized ball and got all the way up to 2/3 of a 5 gallon bucket. It wasn't tumbling but I turned it by hand twice a week. I was dosing 10ml of chaetogrow per week and using red lava rock and miracle mud as a substrate. Nitrate 40-60 and phosphate off the chart (>2.5).

It was growing about 20% per week - OK but not great. The chaeto was very green and nice firm strands like a brillo pad. Then disaster struck.

I read that you can get chaeto to double every week if you dose extra iron so I dosed 5ml of Ferrion. I also had rocks keeping the chaeto from moving around the tank. I stupidly removed those rocks and went out of town for 3 days.

When I got back, my mass of chaeto had slid into a corner, out of the light and out of the flow. A third of my chaeto was dead and the rest was slimy and breaking upon touch.

After a few weeks I was back to a softball sized chunk and it refuses to grow - or die! I put everything back like it was, but nada. I experimented with more flow but it started shrinking and breaking off, so I dialed back the flow. I continued iron dosing. My lighting is unchanged.

What do you think caused the die off - lack of flow, light, or both? I'm confused because people ship this stuff in the mail so it must be able to do without light and flow for a few days.

When I returned it to the light and flow, it no longer grows.

Could it be the iron? Can too much iron cause chaeto to die or not grow? Or have I just not managed to find the sweet spot again with flow?

 

[Subsea]

It’s not too much iron.

“I read that you can get chaeto to double every week if you dose extra iron“
Where did you read that? Every 28 days is realistic and chaetomorphy is not the best or fastest.

Is this a macro algae grow out tank? Aside from dosing chaetogrow & iron, how are you maintaining calcium, magnesium & alkalinity?

 

[Kelliwilliams817]

It’s not too much iron.

“I read that you can get chaeto to double every week if you dose extra iron“
Where did you read that? Every 28 days is realistic and chaetomorphy is not the best or fastest.

Is this a macro algae grow out tank? Aside from dosing chaetogrow & iron, how are you maintaining calcium, magnesium & alkalinity?

I saw a time lapse Jake Adams did and some people talking on Reef Central. I maintain Ca, Mg, and Alk with weekly water changes. Would a chaeto only tank really use up those elements, though?

The only thing I changed about the water was dosing the ferrion... up until that point the chaeto was growing. Are you thinking it was the lack of light and flow over the three day weekend?

 

[Subsea]

I saw a time lapse Jake Adams did and some people talking on Reef Central. I maintain Ca, Mg, and Alk with weekly water changes. Would a chaeto only tank really use up those elements, though?

The only thing I changed about the water was dosing the ferrion... up until that point the chaeto was growing. Are you thinking it was the lack of light and flow over the three day weekend?

Yes, a macro algae tank will suck up all nutrients, including heavy metals, like a sponge. I dose liquid kelp concentrate and ammonia.

3 day blackout may have triggered die off, I don’t know. I think it more likely that a trace mineral became depleted.

 

[Subsea]

“Would a chaeto only tank really use up those elements, though?”

Gracilaria Parvispora grows much faster than Chaetomorphy. When I sent Red Ogo off for analysis at a regional agriculture lab, N to P ratio was 30 to 1. The K to N ratio was 5 to 1 and therefore the K to P ratio was 150 to 1. Also, both Cu & Zn showed 2 & 4 ppm in seaweed biomass when each element was below the detection limit of 10 parts per billion in the water.

PS: I grew seaweed in a 10K gallon 20’ by 40’ green house. Growth rate doubled every 20 days, not every 7 days. In a phytoplankton culture, doubling biomass in 10 days is easily achievable.

 

[Kelliwilliams817]

Yes, a macro algae tank will suck up all nutrients, including heavy metals, like a sponge. I dose liquid kelp concentrate and ammonia.

3 day blackout may have triggered die off, I don’t know. I think it more likely that a trace mineral became depleted.

Does liquid kelp fertilizer provide all the trace elements you need, in your experience? Is this a good one:

GS Plant Foods Liquid Kelp Fertilizer – Suitable for Organic Growing, OMRI Listed Seaweed Concentrate for Lawns, Gardens & Soil​

 

[Kelliwilliams817]

“Would a chaeto only tank really use up those elements, though?”

Gracilaria Parvispora grows much faster than Chaetomorphy. When I sent it off for analysis at a regional agriculture lab, N to P ratio was 30 to 1. The K to N ratio was 5 to 1 and therefore the K to P ratio was 150 to 1. Also, both Cu & Zn showed 2 & 4 ppm in seaweed biomass when each element was below the detection limit of 10 parts per billion in the water.

PS: I grew seaweed in a 10K gallon 20’ by 40’ green house. Growth rate doubled every 20 days, not every 7 days. In a phytoplankton culture, doubling biomass in 10 days is easily achievable.

Does chaeto strip out Calcium, Mg, and alk?

 

[Subsea]

Does chaeto strip out Calcium, Mg, and alk?

YES

 

[Subsea]

MARINE BIOCHEMISTY 201

Photosynthesis is where the organic and the inorganic world come together. Carbon dioxide dissolves in water to form bicarbonate which becomes glucose during photosynthesis.

 

[Kelliwilliams817]

YES

Do you mind if I pick you brain a bit? Besides ca mg alk, liquid kelp, ammonia, is there anything else you dose?

 

[Subsea]

Do you mind if I pick you brain a bit? Besides ca mg alk, liquid kelp, ammonia, is there anything else you dose?

Silicates come in with my groundwater. Middle Trinity Aquifer at 950’ has a TDS of 1050 ppm. When I do a partial water change, it takes less salt to bring it up to full strength.

PS: Sometimes sulfur comes in with groundwater and I can smell it. For drinking & cooking water, I use 7 stage RODI.
For batteries, I use distilled water.

 

[Subsea]

Does liquid kelp fertilizer provide all the trace elements you need, in your experience? Is this a good one:

GS Plant Foods Liquid Kelp Fertilizer – Suitable for Organic Growing, OMRI Listed Seaweed Concentrate for Lawns, Gardens & Soil​

I would think so. Because liquid kelp is organic, I don’t know how to break down individual inorganic minerals so I don’t have dosage rates calculated. I suggest less is better than more. I dose liquid kelp twice a week. I dose ammonia twice a day during lights on.