Where oh where has my coralline gone?


New member
I have a question that I would like to ask you all regarding coralline algae growth. I have a 20 gallon long tank primarily filled with SPS corals, with the exception of a few soft and LPS corals, that is lit with two 65 watt PCs. The corals all have beautiful color, and were grown from frags. They are doing great. The problem is that for some reason I cannot get coralline algae to grow to save my life. As far as trace elements are concerned, I follow the same procedure that GARF uses. I put a capful of Reef Plus, Reef Complete, and Reef Calcium in the water on Sunday and Thursdays, and for my make up water I use RO water with 1.5 tsp of Reef Builder and 1.5 tsp. of Reef Advantage alternating them each week. The tank is continuously filtered with a CPR BackPak, and has sugar sized sand and live rock. I have a 55 gallon FOWLR that has coralline algae growing everywhere. It is lit with one 48" strip and has crushed coral. After talking with the owner of my LFS I was shown in his systems how the tanks with larger sized substrate had way more coralline growth than the tanks with smaller sized. Do you guys know of anything I could do that would help the growth?? Anyone tried Purple Up? Any help would be greatly appreciated.

Dustin Daley


New member
There is coralline algae on some of the rocks in the tank, but it is what was there at the time of purchase. lol I cannot tell that it has grown or spread to any other rocks at all.


YOU have been ignored!
How long has your tank been running? Mine took a good 5 or 6 months to start show coraline.. Now its been about 10 mos or so and Its really taking hold bigtime... No real supplementation other than Ca reactor and time...

So if you haven't had your tank runnign very long then I'd say give it time. I think its virtually impossible not to get coraline in your tank going at some point. I'd say just keep your alk and Ca in line and let nature take its course. Of course getting some coraline covered rocks to seed your tank might help.



Premium Member
The other thing I didn't know is, apparently coraline grows a lot better in low light. My 58 with heavy T5 lighting is about 8 months old, and has maybe 10-25% of the walls just now covered. My fuge/sump is a 100 gallon Rubbermaid poly, has cheapo weak PC lighting, and that started growing coraline within three weeks of setting it up.


New member
Check your magnesium level. at least 1250, and start supplementing with strontium...just go slow with the Sr and back off when the coralline takes off. It's tough to test Sr accurately with hobby tests, even Sailfert.



Active member
I agree with RokleM. I think the answer is that you have 130 watts of light over a 20 gal tank. The SPS love it but I've found that coraline likes lower levels of light. It does grow under high light, but slower in my exprience.

Mike O'Brien

New member
You need to test for alkalinity and calcium. Every tank is different and they all need a certain ammount of suppliment . That can only be determined by testing. If you keep you're calcium over 400 and you're alk and mag in line it will start to grow.

When did pc's become high lighting ?