Raising nutrients and polyp extension

[Space heater]

A couple weeks ago I noticed a lack of growth from my acros and a generally pale look. They had all of the same colors, just not very vibrant and there hasn't been much growth. Meanwhile my monti caps, stylo, and BN have been growing fine, lots of coraline growth. I also noticed that I was slowly having to wipe the glass less frequently. All of this was happening very slowly, over a couple months, so it took a while before I realized what was going on.

When it became apparent I started feeding a bit more, adding aminos and micro food (zooplankton). Since then my skimmer has been much more productive, I have tons of pods, a small amount of HA growth, and to my delight all of the acros have amazing color. They have also visibly started to grow again (lots of encrusting, new tips).

Throughout this I have undetectable nitrates and phosphates. My other params have been stable with Ca 440, Alk 9.0, Mg 1420, pH 8.2, sg 1.25.

My question is that before all of this started I had great PE on all my acros, which never seemed to go away even with the falling nutrients. As soon as I "dirtied up" my tank I have 0 PE during the day and only minimal once the lights go off in the evening. Is this normal? I see tons of great pics of colorful SPS with lots of PE, so I'm wondering why mine quit now that they look so much healthier.

As a side note my zoas have gone nuts since upping the feedings to the point that they're a problem. In two weeks they have probably grown by 25%. I'm seriously considering nuking them with preoxide or kalk paste.

 

[MRJ]

With low po4 and no3 I would keep kh at 6.5 to 7.5 still great growth. Pale can lead to death alk becomes harsh in a low nutrient enviorment. Also potassium becomes important you want to maintain 380~ my corals took 9 months to train the polyps to be out all day. They use to be extreme only at night. Coral vitalizer is a great product. I think if your potassium is good thrn dropping your kh will show better pe.

 

[SoloGarth]

Raising nutrients and polyp extension

Polyp extension is one of those things that seems to happen in tanks with all sorts of different parameters. Not really sure as to why. I have crazy PE on all my acros (green planet has PE about a 1/4" long) to the point where I felt worried something was wrong a while back. But they continue to grow and look good. If you have low nutrients (I run bio pellets) you need to feed a lot. I feel like flow is the most important factor for PE though. Lots of flow. So feed, keep all below 9 and lots of flow.

Also nutrients, flow and light intensity are all intertwined so that if one changes the others may need adjusting.

 

[sprite]

I have decent polyp extension in the day, but it's completely gone till the lights come on again the next day