I just listened to the Macro Algae podcast and I read the article. I have algae growing in my tank and I need help identifying it so I can know better what I should do. I checked out the links provided in the article but I still do not know what it is. I am sure someone out there knows what it is and can help.

I have a 100 gallon mixed reef tank. I have one 150 watt MH and two 96 watt Actinic. My flow rate is about 900 gph. My nitrates are high (20 ppm That is why I removed my bio balls) but all of my other levels are good.

The purple one started to grow when I installed my MH and covered all of the sand and my LVR. My sand sifting goby keeps my sand clean and during every water change I remove as much as I can from the rock. I have been able to get rid of most of it but it still grows on some spots,

I began to see the brown one about 4 months ago and it was growing really slow. Within the last month it has accelerated three fold. The only change I made in my tank was I removed all of my bio balls and removed my carbon filters.

The purple is cyano.

I can't tell what the other is, but it is obviously a nusiance algae.

I would say, the high nitrates, being symptomatic of a nutrient rich system, coupled with the new lights has started this commotion.

Reduce your photoperiod. What corals do you have? Do you need a long photoperiod? If not, reduce it and therefore starve the cyano of the light it needs.

Increase the flow on and around the sandbed and affected rocks. This will keep the algaes down too.

Reduce the nutrient load itself. Perform water changes and lower the feeding for the system. Starve the stuff out!

Dave

No I do not need a long photoperiod. I have a couple of soft coral (Zooanthids, hairy mushrooms, and Lemnalia). The only thing that requires a lot of light is my electric clam. I have my MH on for about 6 hours and my actinic on for about 12 hours (That includes the 6 hours with the MH). I know it sounds like a lot but I have a 150-watt MH and my tank is about 30 inches tall. I was told I needed more wattage because of the height. I have the light on longer to compensate for the lower wattage. How long of a photoperiod would you recommend?

Well.. the clam, I'm guessing, is an "electric" or "flame" oyster..that do not have high light needs. Tell me if I'm wrong.

I would drop the actinics to just 8 hours. 1 hour before and after the MH lighting comes on and off...see how that goes.

Increase the flow on the sand bed and rock too.

Dave

for the brown looking algae, i have seen it before in a LFS tank. i dont know its name but it was removed by a VERY aggressive skimming regimine for a couple of weeks. the owner was emptying the collection cup every day sometimes twice a day.

Well.. the clam, I'm guessing, is an "electric" or "flame" oyster..
you mean scallop, right??... ;)

I appreciate the quick responses. I will shorten my photoperiod to the 8 hours recommended and I will be diligent about changing my skimmer cup daily. I will let you know how it turns out.

I have always called it an electric blue clam but I think the scientific name for it is, Tridacna crocea. Again I appreciate the help and thank you.

honestly to me i think ur tank is in need of light. also hav u checked ur bulb. in addition to things that other peeps on here suggested like changing water, increasing flow, u may consider changing bulb if its been a long time since u first got it. i think having more light of the correct intensity may actually increase good algae growth and slow down the bad ones. correct me if im wrong...

Rob, yes I meant scallop.. again, thanks for the catch!

Goat.... that is, in fact, T. Crocea... one of the more light loving clams kept in aquaria. Yes, you need to keep it lit. I'd not mess with the MH photoperiod at all. I would, however, kick the actinics on for one hour before the MH and have them turn off 1 hour after the MH for a total of 8 hours...FOR NOW.

Adjust your flow, reduce the introduction of nutrients (rinse foods, feed less etc.) and see how it goes from there.

If your actinic bulbs are more than 6-8 months old..or if your MH is more than 6 months old, the spectrum given off by the bulbs may have "strayed" into the temperatures that encourage algae growth. If needed, swap out the bulbs.

Dave

Hi goathead76,

:welcome: to TR