reasons to dye. Help and ideas needed

[mcarroll]

4 hours ago, kotlec said:

 Are you saying that being in more calm conditions can be harmful  ?

  My head goes round.

Look up the coral boundary layer...should help cement the issues:  https://www.google.com/search?q=coral+boundary+layer

[kotlec]

I honestly thing that none of corals are in a such low current that boundary layer problem can occur at all.

I can make video for more corals swaying  if that can help ?

Since my attempt in increasing Po4  my montipora fire digitata doubled in polyp size. Also hammer that has open mouth have shut up. I thing those are good signs that we are moving right direction.  2 of 3 scrubber screens are still in place.  In few days I am planning to test for PO4 again and decide how to proceed.

Yesterday Testing did not show any difference though seems like corals are reacting to some extent.

[mcarroll]

4 hours ago, kotlec said:

I honestly thing that none of corals are in a such low current that boundary layer problem can occur at all.

It's a situation of gradients, not a checkbox unfortunately.  

 

For example, if the bulk tank water has a high phosphate concentration, then even a small amount of boundary layer penetration may be perfectly adequate.  But under low-phosphate conditions, it could take a lot more exchange with the outside water (ie higher flow) to satisfy the same phosphate need.

 

Permutations are endless and corals, generally speaking, are very adaptable feeders, but like anything else they aren't without limits.  

 

So a specific PO4 level that might be fine for a coral in high flow, might potentially be too little for the same type of coral in medium- or low-flow.

 

Relative light levels might play a role in these differences too.

[kotlec]

Ok. Now I get it.  Thanks for explanation.

[kotlec]

Reporting on situation for those who follow.

After increasing nutrient level  most of corals responded positively. Especially LPS corals look more inflated and bit brighter in color. 

Staghorn acropora lost some coloration and I see less polyps though.  

 

Phosphates are at 0,04 and nitrates 5  now. Not sure if I want to increase nutrients more as acroporas started to react negatively.

Reporting on situation for those who follow.

After increasing nutrient level  most of corals responded positively. Especially LPS corals look more inflated and bit brighter in color. 

Staghorn acropora lost some coloration and I see less polyps though.  

 

Phosphates are at 0,04 and nitrates 5  now. Not sure if I want to increase nutrients more as acroporas started to react negatively.

[tzink]

Came here really expecting a conversation about using food coloring in the tank water or something...

😄

But in the process learned a lot about PO4!

[mcarroll]

4 hours ago, kotlec said:

Reporting on situation for those who follow.

After increasing nutrient level  most of corals responded positively. Especially LPS corals look more inflated and bit brighter in color. 

Staghorn acropora lost some coloration and I see less polyps though.  

 

Phosphates are at 0,04 and nitrates 5  now. Not sure if I want to increase nutrients more as acroporas started to react negatively.

Reporting on situation for those who follow.

After increasing nutrient level  most of corals responded positively. Especially LPS corals look more inflated and bit brighter in color. 

Staghorn acropora lost some coloration and I see less polyps though.  

 

Phosphates are at 0,04 and nitrates 5  now. Not sure if I want to increase nutrients more as acroporas started to react negatively.

Keep in mind:  You are fixing a problem with a major necessary nutrient.  You are not introducing some weird chemical.  That goes for any kind of coral.

 

Your Acro's, along with your other corals, have just been through a bout of zero nutrients and what-all that entails (see: Is the coral-algae symbiosis really ‘mutually beneficial’ for the partners?).

 

You were seeing effects on your LPS but not on your Acro.

 

Guess which coral is more suited to a low-nutrient environment, generally speaking?  

 

Acro.

 

Acro's have a much thinner boundary layer, which allows for much greater access to limited nutrients in the water – so even as levels dropped toward zero they may have had adequate levels of nutrients for quite a while longer than the LPS.  

 

LPS are the opposite, with a much larger boundary layer (including tissue depth) they have much more limited access to water-borne nutrients...so when nutrient levels decline, they feel it first.  So you see it first.

 

The fact that Acro's started showing signs of stress just tells me you were in the nick of time to figure this out and start dosing nutrients.

 

0.04 ppm might plenty – keep watching your corals and DO NOT let levels return to zero again.  👍  Higher levels of phosphate don't seem to have any more effect than "enough"...sorta like how calcium is....you can overdose calcium by a ton (I've measured 900ppm before, on accident) and not really see an issue...corals might even look a little happier.  Likewise for phosphates.  Even studies with Acro's where PO4 was taken WAY over 1.0 ppm the corals just kept looking more and more healthy, with no apparent signs of stress.

 

So be confident that you've fixed a problem, not created one.  

 

But your corals have still just been through the wringer (see linked article) so you should expect any and all side-effects in the next few weeks while the corals that weren't too badly damaged get back on track.

 

Some corals that change appearance during such stress don't return to their former color, or it takes a long time for them to do so.

[kotlec]

Was feeling so lonely with my problems for a while. Now you made me feel more confident  and this hobby seems more and more friendly to me.

Thank you very much again.  

 I'll try to update my progress that others in similar situation can learn along with me.

 Hammer looks much better too.

[kotlec]