New member
Can hair algae come in on a frag?
Im having some unsightly HA problems and was wondering if possibly it came in on a few frags I got from a fellow reefer.
Its a fairly new tank and I only use RODI that has a dual TDS meter on it reading 0 out 49 in.
All 6 of my t5s are new except one.

thanks as always RC! :eek:
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-RT * ln(k)
Yes it can come in on a frag. I reckon it is around in most systems anyway unless they are started with completely sterile dry rock. The key is not to avoid its presence but rather to control its growth. For example you almost never see hair algae in my tank unless I go a month or more without a water change. Then it starts to spread. Once I get the water cleaned up and pull it out you won't see it again until the tank gets dirty again.

In my little tank I used some brs dry rock. That stuff must be loaded with phosphate because hair algae is about all that would grow in there for the first year or so.


-RT * ln(k)
What I meant by that is that it is a bit of a pipe dream to think that you can run a tank and never ever have exposure to hair algae. Just get that out of your head. Learn to keep it from growing. Starve it out.


New member
Thanks so much! I've been doing regular water changes every week and like I said I use RO DI water. I bought some turbo snails and someone suggested emerald crabs but I had bad experiences with emerald crab and coral. It's so discouraging because it's a new tank



I've experienced the same with Marcos Dry rock on my setups, but over time (>1 year), it's gradually gotten under control. I wonder whether the acid treatment before using the dry rock is worth the time? I have about 20 lbs leftover and was thinking of doing this treatment.


It may be necessary to do some manual removal if the HA gets out of control. How's your nitrates and phosphates?


Premium Member
The acid treatment might help. If I had enough trouble with the rock, I'd do that, or cure the rock in a tub and dose lanthanum chloride to remove the phosphate. The advantage of the lanthanum chloride is that it's safer to handle. The curing process will be longer than the acid dip, although you could cure with saltwater and kill two birds with one stone.


New member
Hair algae can come on anything from the sea/other tanks that isn't living tissue. This includes frag disks and even snail shells.

Turbos will definitely help with the algae. The best solution is to control nitrates and phosphates. I do this by dosing vinegar and keeping a lightly stocked tank.