Little growth in coral for months (pictures)

[Zpmada]

Hello all,

I have a few coral frags (Mycedium robokaki - low under rock shelf, Leptastrea - low rock in the open, and Flower pot?-middle open rock), that I'm just not having much luck getting to grow much. They still look about the same as I purchased them as frags several months ago. Wondering if anyone has advice?

I've moved them around, and changed lights, and even pumps.


Lighting

Currently, I have two 48" TrueLumen Pro LED Aquarium Light "“ 453nm Blue. I have them on about 11 hours using the Current USA rapid timer pro max intensity set to 100%. I used to also have a white LED channel set to 50% max intensity, but had GHA. Using only the Blue LED, I haven't had any GHA.

Pump
Water pump is the Vortec MP-40 set to lagoon (yellow mode) about 4/12 of the way.

I have an Aquaclear 70 with sera filter wool, a bag of Dr Foster & smith pelleted carbon, another bag of BRS granular ferric oxide.

Finally, I have a Reef Octopus Classic 100-HOB skimmer. (no refugium)

Water condition
Water temp is 80F, and I do 20% water changes ever 1.5 weeks using Instant Ocean Reef Crystals salt and RODI water (0 TDS).

Any suggestions?

Thanks!

 

[Anemone]

The limits to growth are lights, nitrate and phosphate. Since your LED lights seem to be pretty strong, that would lead one to nitrate and phosphate. What are those readings?

Kevin

 

[Oldreeferman]

I feed all my corals at least twice a week min and i didn't see anything at all about feedings in your post, reason im wondering is i know my LFS also does not feed the coral frags just adds amino acids etc & they don't do well until I take them home & feed them real foods. On aminos alone they starve & wither away. I do know that unless the tank has some food source nutrients corals will not grow well if never spot fed, survive maybe but not much else. The ones i now have are over double in size from the frags i purchased & i recently was at the shop again & yup all the frags are still not growing & are actually getting smaller & he runs fancy Kessils I run reg 25w T5s in purple & O2 blue.