Is All Phosphate Available To Corals?

[Clownfishy]

I have always had high phosphate levels and have been battling them with NOPOX. I am currently losing a lot of my lps corals and trying to work out what it going on (please see my other posts below). I am going down many rabbit holes as I try and save my corals but I have a question (which could be a dumb one) to see if I maybe staving my corals.

My Question
Although water test (both ICP and Hanna checker tests) show high phosphate and Nitrate (hanna tests), could something like NOPOX make these available to corals? It seems a dumb question because my water tests show sufficient phosphates and nitrates but could NOPOX be adding bacteria which is able to consume these nutrients quicker than corals can access and consume them? This does not even make sense to me but is it possible to starve corals even though tests are showing there is plenty of nutrients in the water because the bacteria is outcompeting the corals.

Nutrient Levels
My corals (only lps corals) have been dying regardless if my levels are high or low but I dose NOPOX as 2ml per day in a 75 litre aquarium which seems a lot for me. Even at these levels, the best I can get my phosphate down to 0.1. I have tried nutrients levels below and nothing is making a difference

• Phosphate 0.3 - 0.1
• Nitrate 18 - 6

My LPS Loss Threads
https://www.reef2reef.com/threads/all-lps-slowly-dying.901028/
https://www.reef2reef.com/threads/worrying-icp-test-losing-corals.900500/

Many thanks for any help

 

[ss30]

Why are you trying to lower Po4?

Looking at your build thread I know you say your lights are at a low setting but the are on for too long even with ramp up and down I wouldn't go longer than 12 hrs even10 hrs would be plenty. I know you PH drops but your fish and corals need to rest this could be killing your LPS.

Po4, I think you have to many fish for your tank. If you are not getting algae problems I wouldn't worry to much about your Po4 but the best way in your tank to deal with them is to do big water changes every week.

 

[taricha]

PO4 tests pretty much only detect reactive PO4 - the same form available to organisms.
one exception - very high Silicate (several ppm Si) can show up as false positive for PO4 - this is unlikely, though.
barring that, Neither the PO4 level nor its relationship to your carbon dosing is causing the coral deaths.
Look to other explanations.

 

[mdb_talon]

In my experience LPS health and growth have little to do with a specific phosphate level and a lot to do with feeding. If i feed heavy and phosphates are low or "high" my lps generally thrive. If i feed light(like when out of town for a couple weeks) they start looking sad even if the phosphates are "high". I would worry less about having phosphates available and more about other "food"....fish poop, lps pellets, mysis, etc.

 

[Tankkeepers]

In my experience LPS health and growth have little to do with a specific phosphate level and a lot to do with feeding. If i feed heavy and phosphates are low or "high" my lps generally thrive. If i feed light(like when out of town for a couple weeks) they start looking sad even if the phosphates are "high". I would worry less about having phosphates available and more about other "food"....fish poop, lps pellets, mysis, etc.

This has also been my experience with lps as well they need large feedings at least once a week 2 or 3 times being better

I feed mine a paste of reef roids mysis brine and krill choped fine and mixed together into what looks like nasty tooth paste they love it

 

[Tankkeepers]

Generally all coral needs to eat and be spot feed

 

[Hans-Werner]

I don't know whether to respond here or better in the ICP thread but I see one problem: Very low iodine concentration. Everything else in the ICP-OES analysis seems quite fine.

Besides the absolute concentration, which seems ok to me, a rapid drop in phosphate concentration may affect corals.

I also see extended mats of cyanobacteria on some pictures and maybe there is a general bacteria problem caused by the addition of too much organic carbon for the capacity of the tank.

To answer your initial question: In general all phosphates are available to corals. They can also feed on bacteria and hydrolyze their storage polyphosphates and organic phosphates to get full access to the phosphates of the bacteria.

These are the ideas that come to my mind when I see the ICP analysis and the conditions of tank and corals.

 

[Clownfishy]

I don't know whether to respond here or better in the ICP thread but I see one problem: Very low iodine concentration. Everything else in the ICP-OES analysis seems quite fine.

Besides the absolute concentration, which seems ok to me, a rapid drop in phosphate concentration may affect corals.

I also see extended mats of cyanobacteria on some pictures and maybe there is a general bacteria problem caused by the addition of too much organic carbon for the capacity of the tank.

To answer your initial question: In general all phosphates are available to corals. They can also feed on bacteria and hydrolyze their storage polyphosphates and organic phosphates to get full access to the phosphates of the bacteria.

These are the ideas that come to my mind when I see the ICP analysis and the conditions of tank and corals.

Funny enough, everytime over the last few years I have received my ICP test, iodine was always low. I have never dosed it but his maybe a consideration. I certainly have an issue with keeping phosphate below 0.2 and I am assuming the rocks are leaching it.