Chaeto and minor/trace elements

[Willito]

I have a large DIY Chaeto reactor that I suspect is growing algae too well, therefore has become too efficient at exporting nutrient and trace elements. In the past 3 months, I've pruned roughly a basketball-size to toss away every 3-4 weeks. Tank is a mixed reef with roughly 25 fish which are fed moderately on pellets and frozen. Chaeto reactor is 3 months old and after a few weeks of operation, the stony corals like acropora, chalice, favia, and goniopora have faded and slow to grow. I dose Nitrate and Phosphate to keep it in range but it drops to zero if I don't. Reactor has 3 led T8 lights which are lit for 12hr on 12hr off. I've reduced it to 8hr/16hr to slow down the growth, and may reduce further to 1 led light and 6hr/18hr.

Monthly 25% water changes did temporary perk the corals up for a week or two and then back to being lack luster. I've read that Chaeto absorbs plenty of Iron, Iodine, and Manganese, along with others. Question is what else and at what rate? I haven't done an ICP to confirm, don't plan to as I have an old school mentality of reefing methods. Let me know your thought on this plan to reset the parameter and hopefully revitalize the corals.

Option 1
- WC 50%
- Add K+ and A- to my two part dosing, along with C addition weekly
- Reduce reactor photoperiod to 8hr/16hr, reduce to 1 LED light from 3

Option 2
- Bolus dose K+ , A- and C (not certain on the amount to add)
- Add K+ and A- to my two part dosing, along with C addition weekly
- Reduce reactor photoperiod to 8hr/16hr, reduce to 1 LED light from 3

Would really appreciate your opinion on this Randy. Thx

 

[sgdnycct]

What size tank? What’s your fish load?

That’s correct that chaeto ( and any algae for that matter) will absorb many elements. You can cut the photo period way down- I think 4 hrs will keep it healthy- and also trim the macro to a smaller size and keep it smaller. The larger it is the quicker it multiplies. You could focus on adding just some trace elements but I think if you cut it down and slow growth rate + water changes you should be ok. I’d go with option A though v adding so many chemicals as you could overload on some and kiss others.

 

[ShakeyGizzard]

my 2 cents, my nitrates and phosphates dropped to 0 zero with a refugium, i ditched the chaeto, tank is more manageable with water changes and minor dosing.

 

[Randy Holmes-Farley]

I agree with the above suggesting to cut down the photoperiod to maintain your target nutrient levels.

 

[Willito]

What size tank? What’s your fish load?

That’s correct that chaeto ( and any algae for that matter) will absorb many elements. You can cut the photo period way down- I think 4 hrs will keep it healthy- and also trim the macro to a smaller size and keep it smaller. The larger it is the quicker it multiplies. You could focus on adding just some trace elements but I think if you cut it down and slow growth rate + water changes you should be ok. I’d go with option A though v adding so many chemicals as you could overload on some and kiss others.

System is 550G, about 25 fish, roughly 100 pieces of corals 1"-3" size, 6 leather colonies. No inverts. All major parameter are in range, just unknow levels for minor/trace elements.

You think reducing to 4hrs will still keep them healthy? Will give it a try. If it melts i can easily replace.

 

[Willito]

Would you agreed that dosing A- and K+ is more beneficial then dosing something like Chaeto Gro , which is not a full range of elements? My focus is on the coral's healthy and no so much Chaeto.

 

[sgdnycct]

Would you agreed that dosing A- and K+ is more beneficial then dosing something like Chaeto Gro , which is not a full range of elements? My focus is on the coral's healthy and no so much Chaeto.

I don’t know how precisely Chaeto-Gro aligns with what macro algae absorbs. Assuming it’s accurate (which I suspect it is) you might be better off so you don’t get out of balance with elements supplement.

 

[sgdnycct]

What size tank? What’s your fish load?

That’s correct that chaeto ( and any algae for that matter) will absorb many elements. You can cut the photo period way down- I think 4 hrs will keep it healthy- and also trim the macro to a smaller size and keep it smaller. The larger it is the quicker it multiplies. You could focus on adding just some trace elements but I think if you cut it down and slow growth rate + water changes you should be ok. I’d go with option A though v adding so many chemicals as you could overload on some and kiss others.

System is 550G, about 25 fish, roughly 100 pieces of corals 1"-3" size, 6 leather colonies. No inverts. All major parameter are in range, just unknow levels for minor/trace elements.

You think reducing to 4hrs will still keep them healthy? Will give it a try. If it melts i can easily replace.

Hmm you don’t seem to have a big fish load for that size tank. Corals hard to judge but I’d keep an eye on things even after reducing the macro growth. Maybe the corals themselves are doing a lot of the absorbing.

Ive heard 4 hrs will keep it going. Although I’d start with cutting it back too a smaller size and maybe cut to 6 hrs. You don’t want it to die off in the tank.

 

[Randy Holmes-Farley]

Would you agreed that dosing A- and K+ is more beneficial then dosing something like Chaeto Gro , which is not a full range of elements? My focus is on the coral's healthy and no so much Chaeto.

A and K has some things I do not consider useful (eg., barium), but both work and I am not in a position to say which is better for chaeto. I do have confidence in TM and personally would elect it for a tank overall.

 

[Willito]

I'll stick with TM elements for now and reduce the photoperiod, hopefully that turn things around.

I did plenty of research prior to implementing the Chaeto Reactor, mainly to manage nitrate and phosphate with the heavy fish I had in mind. The result and experience thus far, just after 3 months, has surpassed my expectation. Absorption rate is way more rapid than expected, especially with trace elements which I had not fully accounted for. IME, water changes will not keep up with the rate that Chaeto can absorb if a substantial amount is being harvested regularly. This has been a good learning experience, and in hindsight, I should have just converted my biopellet reactor to Chaeto rather than building this huge custom one.