Can't keep Halimeda alive

[phobos2deimos]

Okay, this is weird. Had plenty of reef tanks, currently have a mixed reef/heavy macro tank. I've gotten halimeda shipped and locally, two difference species, and neither thrives.

The first one I got locally, under 120w white/blue LEDs, tried different spots all over my 35 cube and it just turned dark green with cracks of white and died over the course of a month. Tried high flow, low flow, high light, low light, every combination in between. Tried putting it in my fuge to see if the lighting made a difference. Nope.

So I tried again with a smaller-leaved variety that FinzAquatics sent me. This is in my 40b, under full spectrum LEDs. Same thing. It's not dead yet, but it's been dark green with white 'cracks' in it and doesn't seem to respond no matter where it is in my tank.
Everything else is thriving.

N is ~10ppm, P is maybe .5ppm (I really can't remember), Ammonia and Nitrite are 0. pH is 8.2 steady. Temp is on point, 78-9 with no swings.

All I can think is maybe calcium levels, but I used filtered natural seawater here in San Diego, which tons of hobbysists do without trouble, even with SPS tanks (of course those folks supplement). No other appreciable calc uptake in my tank.

Any body have an idea?
I haven't supplemented iron or trace, but my other plants are just starting to show for iron deficiency so I will be dosing that starting today or tomorrow.

 

[FinzAquatics]

I would get the alk and calcium levels tested.

I also dose iodine. Not sure if Halimeda requires that though

 

[phobos2deimos]

I would get the alk and calcium levels tested.

I also dose iodine. Not sure if Halimeda requires that though

I'll give that a shot. While our NSW here should be able to support some calcium load without supplementation, I did just realize that I have a ton of G. Mammillaris in my tank which does require calcium, perhaps that's caused a deficiency. I'll check it out and perhaps start dosing kalk in my ATO. Thanks! PS I've got to ship out a couple more batches of C. Serrulata on Monday, but should have some ready for you after the rest grows out. I'll keep ya posted!

 

[Reefer140]

In my experience, Halimeda loses color under low lighting as well. Maybe try and area with more exposure to the light.

 

[phobos2deimos]

In my experience, Halimeda loses color under low lighting as well. Maybe try and area with more exposure to the light.

Thanks - I've tried it in my fuge, under my 23w CFL, all the way up to directly under my 120w LEDs, and every where in between. Gonna try supplementing calcium a bit and see what happens.

 

[Aquarist007]

Increasing the calcium level is great but I would try supplementing some iron

 

[phobos2deimos]

Increasing the calcium level is great but I would try supplementing some iron

I'm started supplementing iron earlier this month for some other deficiencies, so I'm thinking calcium is right. I just ordered BRS 2 part and the red sea calc/alk/mag test, so we'll see! I'll be sure to update with results.