Purple acro's colouring

[Twistedpro]

Hi Guys,

My tank has been growing well for around 6 months now, growth is through the roof and most of the SPS are coloured to the hilt. The blue's and green's are vibrant as well as the pinks. However i am having problems with my purple acro's. I had one in my local store that had been sitting for ages it was dark brown but had a lovely purple tips around 1" and bright green polyps, another coral that was solid purple.

However in my system they have paled out slighly due to the low nutrients however i have lost the purple. The growth tip turns purple for about 2mm but then the rest just goes a pale brown.

Do some acro's need high nutrients to colour?? Do i have the wrong light (400w 12k reeflux + 2x 24w narva blue's) Is it maybe just the coral placement??

[drives300]

I have read several articles that a nitrate of 5 helps color.

[Dog boy Dave]

If I drive nutrients down in my system all of the colors will fade. Algae growth in my DSB -anemone tank stops. Coral growth slows and perhaps, if I allowed it to continue there would be losses. When I run the system with a high fish load and heavy feeding, purples are deep and vibrant.