urchin in the sump/refugium, advise needed

[danmhippo]

My sump/refugium are covered with green diatoms. Thinking of introducing an urchin to do the job. But need to know if the urchin is going to maw down the macro algae growing in the sump as well?? Need some comments here.

Otherwise, is ther any other ways to rid of the green diatoms without getting my hand (and my rasor blade) wet every week!

 

[scallop]

nice.

 

[SPC]

Damnhippo, I have a Tuxedo urchin in my sump and have found that he tends to get grape Caulerpa stuck to his spines and if not removed they decay. As far as diatoms in my sump/refugium my personal opinion is I welcome them, I figure the more algae in there, the less in the main tank.
I have never heard of diatoms killing snails, anyone else ever heard of this?
Steve

 

[Anonymous]

<BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR>Originally posted by SPC:
<STRONG>
I have never heard of diatoms killing snails, anyone else ever heard of this?
Steve</STRONG><HR></BLOCKQUOTE>

For most of the algae eating snails we keep, diatoms are the main food source. No diatoms = starving snails.

 

[danmhippo]

Guess I will drop the urchin idea. Going back to square one......razor blade.

 

[jmeader]

I've had mixed results with urchins. Sometimes they will eat the plants and sometimes they won't. I'm not even talking about different types of urchins. Even a single urchin will switch back and forth between algae and plants.
Where are the silicates coming from to fuel the diatom growth? Can you eliminate them and let the diatoms die off?

 

[Anonymous]

Originally posted by jmeader:

Where are the silicates coming from to fuel the diatom growth? Can you eliminate them and let the diatoms die off?


You don't have to have silicates to have diatoms in a tank as they are natural.
A few snails or limpets should take care of the problem if it's out of control in your refugium.

Regards,
David Mohr

 

[davelin315]

^ as far as snails are concerned, I've been told that eating diatoms is toxic to snails and that they will keel over and die (don't know if this is true, never had diatoms in my tank or just didn't know it, probably the latter). Urchins are a curse, however, as they will decimate your refugium. I have one urchin in my tank that I brought back from hawaii, it's a tiny little pencil urchin (not the kind you see in stores), but the rest of my urchins are banished to the basement pond as trigger and shark food because they have eaten everything from polyps, to xenia, to macroalgaes, to starfish, to fish. And this encompasses three types of urchin, longspine, common pencil, and black and white hawaiian pin cushion (also imported from a trip there).

 

[danmhippo]

BTW,

David, what kind of limpet do you recommend as I find snails effective on film and green algae, but not so hot on diatoms. Need something that love to scrape off the glass (well, acrylics actually).

SPC, I do have concern of having algae stuck onto urchin's spine and end up being rotted. What worries me more is the seagrass that I am cultivating in my refugium. I would hate to see leaves of seagrass got stuck onto the urchin and the whole patch gotten uprooted.

Jmeader, I too do not seriously believe silicate is the primary mean of nutrient that fuels the diatom growth. I do not have significant growth of diatom in my main tank, but the refugium walls are almost entirely coated with them. I am guessing there are 2 factors, 1. Diatoms in refugium has already used up most of the readily available nutrient (whatever it may be) leaving little diatom growth in the main tank. 2. I clean the main tank glass much more often than I clean the walls of the refugium. Leaving the refugium walls unattended, diatom spreads profusely. Jmeader, however, I think you are on the right track and this got me thinking that its time to add one more test kit to my collection----silica. I currently have no silicate test kits and am also wondering if silica is indeed the culprit of the diatom growth. I would also like to know at this point if my source water contains higher than normal levels of silicate.

Thanks everyone......

 

[Ritteri&amp;Bubbles]

I would think you would want as much algae in your sump as possible. I have a few snails(and I mean few)and a couple of peppermint shrimp in there and thats about all. Also, I use a 65 watt HD plant growing incadescent bulb for lighting, which give me a more diversified array of algae for the tank, I have tons of green corraline algae along with all types of deep water algae it seems too. It has helped my tank out alot.

[ July 31, 2001: Message edited by: Ritteri&Bubbles ]

 

[SPC]

Damnhippo, IMO if I didn't clean the glass in my main tank I would have alot of diatoms on the front glass. I wondered why it seemed to grow on the front glass more than any other place, my first thought was that it just seemed that way because that is the main viewing area. Then I read, on one of the boards, someone saying that most of their current from their PH, etc... goes against the front glass, I know that is the case for me as I have 3 sea swirls mounted on the back of the tank. Their theory was that the algae is in the spot that delivers the most nutrients.
A change of subject if you don't mind, How is your sea grass doing? How much light does it require? I am thinking about doing the same thing.
Steve

 

[danmhippo]

The sea grass is doing well, though not an aggressive grower. The height of the seagrass peaks up about 10". But with the dark and uniform foliage, the refugium looks much more orderly and pleasant to your eye. I also have another refugium with caulerpa. In contrast, the caulerpa (feather) grows everywhere, one runner on top of another. The caulerpa refugium looks much much more disorganized and will make my eye sore from staring at them for a prolonged period of time.

The seagrass is in a 30G tank lit only with a pc lighting, simple. The caulerpa is in a 40G with LOA and NO flora-grow. Both tank lighting hours is 24/7. Both tank harbors large population of pods. However, I do see there is more pods and life in the caulerpa tanks than the seagrass tank as there are more hiding places among the thick growth of caulerpa runners. I would also assume caulerpa contribute more to nutrient output of my tank then the seagrass.