Derbesia

[uglyryder]

i think i may have derbesia from what i saw in the pics on the algae page. but i do have a few questions about it, whatever is in my tank has grown slowly it started as a patch about half an inch or less and it the course of 6-8 months its around 3x2. its not long at all maybe half an inch and also when the lights first come on in the morning the stuff is all most transparent. does this sound like Derbesia??

 

[piercho]

Its green and its filamented, but there is not enough detail in the picture to call the genus. I would guess its Derbesia or Bryopsis. If the fronds look comb-like or feather-like, it's most likely Bryopsis. Derbesia has fine, soft, irregularly branched filaments. Derbesia is best identified by it's grape-like sporangia, but you need a microscope to see these.

 

[uglyryder]

ill try to get a better pic..but either way is this something i need to get rid of?

 

[natan]

Yes u'd better get rid of it, at least if the tank is intended as reef.

 

[piercho]

Control of either these types algae ("hair" algae) is necessary in tanks containing branching stony coral as it gets in the branches and induces recession. It can also grow over some soft and LPS coral. In FOWLR tanks hair algae is not an issue, and may be helpful in keeping certain types of fish such as dwarf angels.

 

[uglyryder]

the stuff growing in my display is very fine like green cotton fibbers.

 

[piercho]

Best guess is Derbesia.

 

[uglyryder]

ive searched and searched and it looks like the best thing is water be weekly water changes of 5-10 gallons. any thoughts on this?

 

[CapitalO]

Ive been battling with derbesia for a while, it takes some serious diligence to win the battle. Ive found that starving it of nutrients only stops its growth. If you stay on top of your water quality long enough, it will eventually recede.

For me the most effective method is manual removal and keeping your water clean (yes, weekly water changes would accomplish this). Also, it loves detritus -blowing off rocks with a turkey baster seems to help, along with good water movement.

You mentioned you noticed it going clear, then turning back to green; Ive observed mine do this too. When you starve it, it goes clear, but if your nutrient levels rise back up, it springs back to life... I hate derbesia aka devil-weed.

 

[CapitalO]

Also, I forgot to mention -take care of it as early as you can. My biggest mistake was letting it get a good foothold. As they say, 'nip it in the bud'

 

[piercho]

+ 1 or what CapitalO has said. Derbesia is not preferred gaze for most fish or the urchins and snails that I have had. For a tank your size some of the dwarf angels like the Cherub angel or algae-picking gobies like the Rainsford goby may pick at it. Combtooth blennies like the lawnmower blenny will not, IME. If you add fish to graze the Derbesia and the fish does not it could just lead to more Derbesia due to more nutrient load on the tank. I would guess that specialized grazers from the Sarcoglassan sea slug family are primary grazers of Derbesia in the wild.