Chaeto for Nutrient Export

[cobra2326]

I thought I'd share my findings from some research I've been doing on using Chaeto to export nutrients in my 10 gallon system.

Lighting: Photosaturation occurs at 400PAR [1]. I'm unsure of how this translates directly to PUR, but BRS talked about it in their review [2].

Photoperiod: I'm not aware of any studies on what ideal is. [1] states they're using 15:9 light:dark but then it appears to be the reverse on their charts. You can definitely see nutrients being reduced more quickly when the lights are on, but a resting period may be necessary. A common method is to use 12 hours on, 12 hours off.

pH: Increases when the algae is lit due to oxygen production and other factors [2].

Nutrient Export: A simple rule of thumb is 10g of dry macroalgae will reduce nitrate by 10ppm and phosphate by .1ppm in a 67-gallon aquarium [4]. For Chaeto, this varies based on the nutrient content of the water [1]. See the charts in [1] for estimates based on nutrient content and aquarium size.

Nutrient Limitation/Imbalance: Growth is P limited when N ratios exceed 11-24. Growth is N limited when N ratios drop below 8-16 [1]. When N is enriched, the algae can apparently transfer some of this for storage in the chlorophyll. Therefore, you may be able to determine nutrient imbalance just by looking at the color of the algae. "N deficiency typically decreases photosynthetic pigments (Falkowski and Owens, 1980)". Iron depletion may require dosing as well, although I'm unsure of symptoms other than slowing growth [5]

With this data, you should be able to estimate the amount of Chaeto needed to export a desired amount of nutrients from your systems and in what concentrations. Hopefully it helps many of you run more efficient 'fuges and solve issues with poorly growing macro.

[1] MARGARITA MENÉNDEZ1 and F.A. COMÍN1. Spring and Summer Proliferation of Floating Macroalgae in a Mediterranean Coastal Lagoon.
https://www.researchgate.net/public...tal_Lagoon_Tancada_Lagoon_Ebro_Delta_NE_Spain
[2] https://www.bulkreefsupply.com/vide...-best-refugium-light-and-what-is-coming-next/
[3] MARGARITA MENÉNDEZ1, JORGE HERRERA2 and F.A. COMÍN1. Effect of nitrogen and phosphorus supply on growth,
chlorophyll content and tissue composition of the
macroalga. http://scimar.icm.csic.es/scimar/pdf/66/sm66n4355.pdf
[4] http://reefkeeping.com/issues/2006-09/rhf/index.php
[5] http://www.advancedaquarist.com/2002/8/chemistry

 

[maddmaxx]

nice write up. good info in there...

 

[mcgyvr]

Oh get outta here with your attempted facts/scientific paper citations...

This is reefing.. We go off fallacies/rumors/wives tails/guesses around here....


Oh wait.. Some of your citations are guesses/unscientific,etc.. too.. Ok.. thats better..

 

[cobra2326]

Oh get outta here with your attempted facts/scientific paper citations...

This is reefing.. We go off fallacies/rumors/wives tails/guesses around here....


Oh wait.. Some of your citations are guesses/unscientific,etc.. too.. Ok.. thats better..

LOL, yeah. I did this because I wanted to estimate what I could expect Chaeto to export. I don't run a skimmer so it's pretty important.

 

[ca1ore]

..... don't forget myths!

 

[cobra2326]

Just thought I'd clarify something on the point of photosaturation. I was thinking about the 400 PAR number in the context of the BRS study and things weren't lining up.

400 PAR is probably not enough if you want to maximize growth, because some of the chaeto will be shaded. I'm not sure you need 1500, but it all depends on the design of your fuge, spread of the bulb, etc.

 

[ca1ore]

FWIW, when I designed my sump (which contains the chaeto section) I elevated it so that I could also light it from below. This appears to have made a sizable difference in growth.

 

[jda]

These are just my experiences over the years, so probably more in the myth category, but chaeto will stop growing out-of-nowhere once the iron is gone. Iron must be supplemented beyond what can be replaced in water changes. Also, need to break the ball up quite often and thin out - less will grow more and soak up more nutrients than a larger tight ball which eventually stops doing much. I have literally found it to grow the best under a screw-in 5500k CFL in a clamp-on 120V fixture - pure daylight spectrum.

Most people don't actually export their chaeto. Once the iron is gone, it can die back and release the nutrients back into the water and most folks don't even notice since the outer part of the ball is still green. Remember that it is not an export until it is exported and is just in transition until then.

 

[ca1ore]

Completely agree. I've been dosing iron (ferrion) for a few years now. Otherwise my chaeto growth was crap.

 

[ericarenee]

its only a myth, untruth , rumor and so on if its NOT On the Internet. if its on the net it must be true.


Thanks for sharing

 

[wildman926]

My ATS's hair algae outcompetes the chaeto for nutrient export. The chaeto has died off for the second time. Hair algae is actually growing in them now!! LOL...Going to pull those chaeto reactors this weekend.

 

[cobra2326]

These are just my experiences over the years, so probably more in the myth category, but chaeto will stop growing out-of-nowhere once the iron is gone. Iron must be supplemented beyond what can be replaced in water changes. Also, need to break the ball up quite often and thin out - less will grow more and soak up more nutrients than a larger tight ball which eventually stops doing much. I have literally found it to grow the best under a screw-in 5500k CFL in a clamp-on 120V fixture - pure daylight spectrum.

Most people don't actually export their chaeto. Once the iron is gone, it can die back and release the nutrients back into the water and most folks don't even notice since the outer part of the ball is still green. Remember that it is not an export until it is exported and is just in transition until then.

I think Randy also said in several articles that he doses iron to keep macros growing well. Everything you said is spot on IMO.

 

[ca1ore]

My ATS's hair algae outcompetes the chaeto for nutrient export. The chaeto has died off for the second time. Hair algae is actually growing in them now!! LOL...Going to pull those chaeto reactors this weekend.

I gave up on my chaeto reactor as well. Simply wasn't necessary in addition to my ATS and the chaeto clump in the open refugium.

 

[JTL]

Where do I get the iron for dosing Chaeto? Mine does not grow and appears to be wasting away. I use GFO, my phosphates measure zero, my nitrates are also about zero, I use a light source similar to an H380 (chinese ko) which has lots of red and a little blue.