What is growing on and near my live rock?     10/12/18
Hi folks,
<Hey Shawn>
I have been using your site for many years and it has always been a blessing and answered every question I had!
<Glad to know it has helped you that much!>
I have a 90gal tank with quite a bit of live rock and very few inhabitants currently (few small snails). Getting the tank ready to stock once again and (outside of some unwanted algae), I have some things that started growing that I have not experienced before. I can't seems to find exactly what these tree/twig looking things are that are growing on and next to my live rock. Kind of remind of Mangrove roots here in FL. Here is a pic of them in the tank and one that got temporarily de-rooted as I was
cleaning tank and bedding while readying for next participants.
<This is some kind of calcareous algae, looks like Halimeda incrassata.>
Regards, Shawn
<Have a nice day. Wilberth.>

Early Autumn for Halimeda?       8/15/18
Hi Crew!
<Hey Dani>
I have been very happy with a Halimeda macro algae I got over a month ago. Yet I have noticed over the last week it is turning a “golden” color on some of the “leaves”. These leaves also seem to be affected by specs of coralline algae and look a bit furry as well.
<I see this in your excellent pic>
I take it that there isn’t really an Autumn season for Halimeda in the ocean lol—what’s it doing?
<Mmm; appears to be "suffering" from a lack in water quality and/or being outcompeted given present conditions. What re your Ca, Mg in particular? Water temp.?>
I have this feeling this older part of the Halimeda is possibly not doing well. I’m by far a reef expert like you all, but I do know some plants try to produce offspring quickly when they aren’t doing so well.
<Agreed; and likely relevant... the month of your having this algae... takes a while for it to adjust or show signs of not doing so>
In the last week I’ve seen multiple sprouts coming out of the rock frag this Halimeda is on. Should I clip off the older plant or maybe just the affected leaves?
<I'd leave all... the calcium et al. in the existing thalli/pads will add to the system>
I have read they do not like being pruned though...or should I wait for the little ones to grow a bit bigger first?
<Again...>
Inserted a pic below. Any feedback is appreciated as usual.
-LED 89w par intensity up to 700, lights on for 7 hours
-2 returns @ 266 gal each
-1k icecap gyre at 700 gph peak
-SG 1.025
-Am 0
-Nitrite 0
-Nitrate <10
-Alk 10
-Calcium 475
-Mag 1400
<These are certainly fine, in fact, a bit high. I'd allow the [Ca] to drop to about 400 ppm, the [Mg] to about three times Ca>
-Test bi weekly with Salifert & dose Seachem reef builder, calcium, & magnesium.
-10% weekly water change with Red Sea
-I only feed frozen twice a week (half cube typically) with a small broadcast of zooplankton (1-2ml), pellets 4 days, and no food on water change day.
-skim aggressively with a Aquamaxx HOB 1.5
Dani
<What is the temperature here? I'd keep in the upper 70's F max; and do you have measurable phosphate? Necessary. Bob Fenner>

Re: Early Autumn for Halimeda?     8/16/18
Hi Bob!
<Hola Dani>
Just tested my phosphates and nitrates too just in case. Phosphates are undetectable and so are nitrates.
<... mate; all life we're interested in need both. This IS the likely cause of failing health here>
It’s summer here in Florida, so my tank peaks at 84F and averages 82F during the day at the moment. I don’t have a chiller so the best I can do is run lights at night and at that time lower the a/c.
<I would cut the lights back, scoot the top/cover a smidgen>
Last week I did remove my chemical filtrants because I felt it was making my water “too clean”—possibly too soon to really make a solid judgment but from this base test, it may show I was right. I reduced my weekly water changes to 10% from 25% as well.
<Good moves>
I do have other macros in the tank including: Codium, shaving brush, blue Ochtodes, Caulerpa prolifera, Padina, an unidentifiable Rhodophyte, and dragon’s breath—all of which are flourishing.
<Ahh; well, these may well be outcompeting your new/er Halimeda. B>
Dani ��
"Adversity is merely fuel for virtue~"
<Not necessarily, or always>
Re: Early Autumn for Halimeda?     8/16/18
Good evening Bob!
<Good morrow Danila>
Well, after listing and realizing how many macros I own, I had a feeling you’d say it was possibly being outcompeted. So ironic—for months I was battling nitrates and phosphates and now I’m one of those looking for them, lol.
<Ahh!>
Well, do you think it wise to wait a week, or few perhaps, to see how the lack of chemical filtrants and reduced % of water changes impacts the tank?
<Yes; this is a sensible approach>
I’ve done further research on Halimeda so I know what it looks like when it’s about to explode spores...appears white and with green fuzzies.
<Good desc.>
I’m not sure my nano tank would handle the ammonia that can build up after they go sexual?
<Mmm; not much ammonia/protein involved here. Likely if your system is fine/balanced, you have sufficient filtration, circulation, and likely "caught" the event early on you'd be fine>
I feel I am dancing on a fine line the way it looks. Today it actually looks a bit better and the babies are growing like Aiptasia went out of style.
<Ha!>
If I still have zip phosphates and nitrates after observing, I’d like to maybe switch to biweekly, or less maybe, water changes before trying to dose stuff just to raise nutrients.
<Mmm; well; I wouldn't purposely "add nutrient/s", but maybe feed your livestock a bit more>
As always, appreciate you and your team’s advice. You all have been helping me since I started with a 45g that ran with a penguin filter (LOL!) over 10 years ago!
Dani
<Glad to find you have stuck with the hobby. Can be trying at times eh? Bob Fenner>