Zoas and Bicarbonates

[ZoWhat]

Embarrassed given my Avatar name that I don't believe I've been cultivating my zoa dominated tank like I should.

Things are average but not great with my zoas

The one area I've just let my salt do the work is with bicarbonates.

Last time I've checked my dKH was around 7.

Just now learning from other posts that ppl that have zoas growing like crazy have Alk more like 10-11 dKH

Again my 6ft 180 is 95% zoas/palys, so willing to keep a high 11dKH tank bc I don't have any SPS or Acros at all

QUESTIONS

1) Is it true that zoas grow more in 10/11dKH than in 7?

2) my pH is normally high with a bottom of 8.1 and a peak of 8.35 during high light. What does that tell me about my bicarbonates/Alkalinity?

3) with me having around 220ish gal water volume, if I were to dose bicarbonate to get up to the 10/11dKH range, what's the best method? Kalk? 2part? Baking soda? BRS Sodium Bicarbonates?

Plz help

 

[Supa]

I’m new and tagging along to learn, I have only a few zoa frags and one colony my current dKH is 8.5 and I haven’t had any issues other then one I got recently that shipping took a day longer then expected(I suspect that’s the reason anyhow)

 

[ZoWhat]

Anyone...

 

[F i s h y]

I cant speak to the growth differences at different measurements of alkalinity. I have zoas that do well from 7.5 to 11. I can tell you that I was dosing baking soda into my 80 gal mixed reef (lots of sps) to compensate for alk drops at a rate of 1.5 tablespoons a day with no major effect on ph.

 

[PeterC99]

Why are you so concerned just about Alk for Zoas? Isn’t Alk much more important for corals that have skeletons?

What about more important stuff like lighting, flow, Trace Elements, PO4 & NO3, Stable parameters, etc.?

 

[Randy Holmes-Farley Verified Community Expert]

I didn't answer because I do not know the answer, and figured zooanthid zealots would know better.

Bicarbonate and carbonate do have uses beyond calcium carbonate formation.

Specifically, since CO2 itself is in short supply in the ocean, many photosynthetic marine organisms attain CO2 from bicarbonate and/or carbonate.

This article describes that process anf which organisms are known to use it:

Photosynthesis and the Reef Aquarium, Part I: Carbon Sources by Randy Holmes-Farley - Reefkeeping.com

for example:

Photosynthesis of Algae Relative to Their Natural Environment
Enough marine algae have been studied with respect to carbon uptake to allow certain comments about their capabilities to collect carbon in relation to their natural habitat. In a study of 38 species of red algae, researchers found that subtidal algae were more often restricted to using carbon dioxide, while intertidal species could typically use both carbon dioxide and bicarbonate. In fact, their ability to use bicarbonate correlated strongly to their positioning along a rocky coastline, with the efficiency increasing with tidal height, except for those species at the very top of the tideline, which showed a reversal of that trend. Similar results have been found for other studies of macroalgae, including green and brown algal species.

Perhaps such relationships relate to the likelihood of spending considerable time in small closed tidal pools, where carbon dioxide would be more limited than in the open water, while at the very top of the shore, where exposure to air is most likely, the algae are again able to gain adequate carbon dioxide. The actual mechanisms used by some species (the brown alga Hizikia fusiforme, for example) that have multiple mechanisms actually change when exposed to air (taking up CO2 directly) and when immersed in seawater (using bicarbonate).

 

[flagg37]

I had one kind of zoa (Mohawks) that took off and practically became invasive. The rest did not (utter chaos, and some others); so in my case, it had nothing to do with alkalinity.

 

[ZoWhat]

I still believe fleshy LPS still derive their tissue growth in conjunction someway with carbonates and bicarbonate.... but at a sweetspot of 9-10 dKH

 

[Cory]

I cant say if they grow better with higher alkalinity but if you want to raise it its best to use baking soda (sodium bicarbonate) if you dont need a boost in calcium. Otherwise use limewater over the course of a few days dripped to raise both calcium and bicarbonate alkalinity.

Considering zoas are fleshy, they would need a lot of nutrients to grow. What is your no3 and po4? You could try maintaining them higher to help with growth too.

 

[Randy Holmes-Farley Verified Community Expert]

I still believe fleshy LPS still derive their tissue growth in conjunction someway with carbonates and bicarbonate.... but at a sweetspot of 9-10 dKH

LPS certainly use it for skeletal growth.

 

[Hooz]

My zoas do well at 9dkh, but I don't know if it's the 9dkh that does it, or the fact that I started paying attention and dosing to get to 9dkh, and all my parameters got a lot more stable. I picked 9dkh because that's where my salt mixed, not because I thought it was some magical number.

I think alkalinity is important for zoas but, IMO, it's more of a combination of things. Nitrates (10-15ppm), Phosphates (0.05-0.10ppm), trace elements, amino acids, etc are all just as important. And we can't forget light!

I hit a 2 month stretch where my tank was too clean and my zoas all looked like crap. I ended up dosing phospahtes and nitrates to get my numbers up... in all my years of reef keeping, that's one thing I never thought I'd have to do... and all my zoas perked back up.

I think the key is to pick your number, make it stable, and then make sure everything else is "good" and consistent. Most importantly, give them time to get used to it before chasing off after another number.

 

[Hairyteeth]

I had one kind of zoa (Mohawks) that took off and practically became invasive. The rest did not (utter chaos, and some others); so in my case, it had nothing to do with alkalinity.

Mohawk and pandoras … owners bewre

 

[Cell]

I would examine those high alk tanks closer and see if they also have high nutrients, which may or may not be the real difference maker in zoa growth.

 

[BrianAnthony]

I read through... My nano 12g has zoas and palys in it. In my 12g nano, things change very quickly. I can tell you that NO3 is important. I must have overdosed my nopox and nitrates went to 0.0. my guys were not happy, only opening up partially for a few days until the nitrates were built up again. While my NO3 was 10, that seemed to be the sweet spot. They were growing and new polyps forming. The strange thing... My pulsing xenia didn't pulse very rapidly during the 10NO3. When the nitrates went to 0... They were practically blinking, which makes sense if their pulsing is for nutrient retrieval.