Phosphate - SPS binding question

[BantyRooster97]

So I saw a video online discussing certain things in our tanks (Alk, cal, mag, phosphate, nitrate, etc) and something caught my attention. It said if a tank has high phosphate, that might affect stony corals (SPS) negatively.

Because the SPS corals absorb the phosphate in their exterior skeleton & that slows or blocks their consumption of ALK/CAL to build more... thus slowing growth of the coral.

@Randy Holmes-Farley is this true? If so, how long until the phosphate is released or used & the corals will start to grow again?

 

[Brew12]

So I saw a video online discussing certain things in our tanks (Alk, cal, mag, phosphate, nitrate, etc) and something caught my attention. It said if a tank has high phosphate, that might affect stony corals (SPS) negatively.

Because the SPS corals absorb the phosphate in their exterior skeleton & that slows or blocks their consumption of ALK/CAL to build more... thus slowing growth of the coral.

@Randy Holmes-Farley is this true? If so, how long until the phosphate is released or used & the corals will start to grow again?

Randy wrote an excellent article on this. Should have at least most of what you are looking for.
http://reefkeeping.com/issues/2006-09/rhf/index.php

 

[BantyRooster97]

Thanks! Gonna start reading

 

[Randy Holmes-Farley Verified Community Expert]

There's some debate on elevated phosphate. Some great tanks have elevated phosphate, and some studies have shown it slows growth.

Do the great tanks with 1 ppm phosphtae just have corals remaining that are OK with it?

Is growth just slow and who cares?

Are reef tanks different than the studies in isolation have suggested?

The trend seems to be heading toward not worrying so much about phosphate and making sure it isn't too low (say, at least 0.01-0.02 ppm), but you will need some other good ways to control algae.

 

[BantyRooster97]

Good read, but what I didn't see was any info on how long that phosphate me be in or affect the growth of corals.

I ask because I have been battling phosphate for a while now (see other posts). I have been stable at .07 for a few weeks (by natural methods) and just introduced some Carbon/GFO in a reactor to get me over the hump & down to .02.

My SPS (that didn't die) have all been in a growth freeze. They are colored up & nice ooking, but I have had almost no noticeable growth in months.

Just trying to see how long this may last. And is it safe to add any new corals yet.

thx

EDIT: Just saw your post Randy, thanks! Guess it's a waiting game like everything else in this hobby.

 

[Randy Holmes-Farley Verified Community Expert]

In the linked article, the term "calcification" means skeletal growth of corals. So this section, for example:

This inhibition of calcification takes place at concentrations frequently attained in reef aquaria, and may begin at levels below those detectable by hobby test kits. For example, one research group found that long-term enrichment of phosphate (0.19 ppm; maintained for three hours per day) on a natural patch reef on the Great Barrier Reef inhibited overall coral calcification by 43%.6 A second team found effects in several Acropora species at similar concentrations.8

 

[BantyRooster97]

so the tank really needs to be at .02 for the corals to grow?

Or it phosphate needs to be lower... ie not at .1

 

[Brew12]

so the tank really needs to be at .02 for the corals to grow?

Or it phosphate needs to be lower... ie not at .1

I'm not sure there is enough information to firmly say any level is required. Some tanks seem to do just fine at 0.1ppm. In my opinion, if you have PO4 at 0.1ppm and your coral aren't growing it is worth trying to bring PO4 down as this is a possible cause.

 

[Randy Holmes-Farley Verified Community Expert]

so the tank really needs to be at .02 for the corals to grow?

Or it phosphate needs to be lower... ie not at .1

Depends on the coral and the goal.

 

[flowflezy]

Interesting battling this myself

 

[BantyRooster97]

Coral - SPS, I had probably 45-50 different SPS when the carnage started, down to 10 now. (Acros, Montis, Pocs) My softies and LPS had no issues.

Just want them to grow.

Names- WD, ORA PB, Garf Bonsai, JF Sour twist, Poker star monti, Green slimer, Purple stag, Vivid RD, Blueberry Fields, Lime in the sky)