Coralline Algae & UV Sterilizer

[DarG]

I thought that this may be a good place to ask this.

Can a UV sterilizer inhibit the growth of new coralline algae?
My last tank had it growing all over like crazy and I did not have a working UV on that system alot of the time it was up. This system has had the UV with regular lamp changes since almost the start and my coralline growth is very very minimal eventhough what is on the rocks has remained. There is quite a bit on the LR but its not spreading. Seems that the UV is the only thing I havent considered. I think Ive looked at everything else.

Anyone?

[Percula9]

I don't think U.V affects coralline growth. Better to check the calcium, alk and magnesium levels.

[DarG]

My parameters are all good. Like I mentioned, Ive gone through everything I can think of. Thanks.

[Icefire]

shouldn't afftect it but uv kill free floating algae spore

[Randy Holmes-Farley]

I do not know if a UV can kill whatever spores the coralline sends out into the water. It won't impact the growth of coralline on rock surfaces once present there.

[DarG]

[QUOTE]<a href=showthread.php?s=&postid=11923253#post11923253 target=_blank>Originally posted</a> by Icefire
shouldn't afftect it but uv kill free floating algae spore [/Q


OK so does Coralline Algae grow on different surfaces by algae spores floating through the water before settling on the growing surface? And if it does, wouldnt it end up going through the UV? And if so, does the UV kill Coralline algae spores? I know it kills other algae types, but does it for sure also kill coralline ?

[DarG]

<a href=showthread.php?s=&postid=11923271#post11923271 target=_blank>Originally posted</a> by Randy Holmes-Farley
I do not know if a UV can kill whatever spores the coralline sends out into the water. It won't impact the growth of coralline on rock surfaces once present there.

OK, so would a particular coralline colony on a rock spread and encrust further parts of that same rock without sending out spores into the free water first? IOW, can it just expand itself and spread without releasing spores into the water? I know for it to migrate to a different surface it would have to send out spores in the water. But to just expand an existing colony on the rock do new spores have to be released into the free water first?

If that makes sense.

Thanks

[Randy Holmes-Farley]

OK, so would a particular coralline colony on a rock spread and encrust further parts of that same rock without sending out spores into the free water first?

Yes. It readily expands across a rock and a UV will not impact that. :)

[DarG]

Ok, so then it's not the UV. The Coralline on the rock is not dying off at all but it also is not growing much at all.

How about GFO. I always heard that coralline was one algae that grows better with very low phosphates. Can GFO prevent growth?

The coralline I have on these rocks was all grown under VHO.
The rock was transferred from that system. I now use halide and T5 supplemental lighting. Is it possible that different strains of coralline grow under different light intensities and that my coralline wont grow much because I am now using higher light?

All my parameters are pretty good. Calcium 430 - 440, Mag. 1300+, Alk. 3.6 meg/L , PH 8.1 - 8.3 ... zero measurable phosphates, zero ammonia, zero nitrates ...

Tanks been up for 15 months + and all I have new are a few tiny spost on the overflow box and one or two on the glass. Where it is growing lately is inside the U-tubes and the inside of the overflow box some. It's growing best there as of the last couple months. I put fiberglass window screen over the u tubes and internal and external overflow boxes to limit algae growth and it helps alot but coralline is growing there since then. So, does my light theory maybe make sense at all?

[Big E]

Yep, it's the light intensity difference. That's always been my experience with coralline growth. I have a four 54" t5 setup (75g)that grows coralline much faster than my other setup with 2x400w 12k setup(120g). They are both plumbed together in the same system.

Take notice of pictures of reefs on the web. The back of the tank always gets heavy growth because it isn't getting direct light. It is usually the light pink corraline that does best in those conditions.

I have a dark purple coralline in my tank that handles the direct light much better.

I doubt the UV is a factor at all. I saw a tank that was loaded with corraline & it had a 80w UV unit on it. The pic was just to prove how the UV has little effect.

[Randy Holmes-Farley]

I don't think the GFO slowed coralline growth unless you really drove phosphate too low. Is anything else growing well in the tank?

The lighting does seem a reasonable possibility. You may also have some other sort of testing error.

Do you skim? Elevated organics may also be a concern.

[DarG]

The tank is not stocked yet. I didnt transfer corals I had traded/sold them a while before I swapped tanks. I have been accumulating new gear and playing with lighting before I start stocking corals. The lack of coralline has also delayed it as I wanted to make sure there wasnt an issue somewhere.

I really dont think its testing error. Ive been doing this a long while now. My test kits are current. I was using a Salifert alk. kit which I thought may have been an issue but a new lamotte verifies the Salifert results.

I skim, 90 gallon tank, DAS EX-2 skimmer.
I do have some fish and shrimp and they are all thriving.

I have never had measurable Phosphate in this tank by test kit and use the GFO as preventative.

Since both pink and some purple coralline are now starting to grow in the overflow ever since I covered it with a screen cover, Im thinking it is the light intensity as well, now. Atleast in part. I dropped my halides to 150 watt and raised the lighting further but that isnt doing much. My 250 watt lamps were reeflix 12K and these 150 watt Iwasakis are close in output. But I have seen photos of Halide lit tanks with tons of Coralline. In fact, several moths ago I asked about coralline growth and halide users, and lots of responses with plenty of growth and some pictures showing it.

When I first switched to halide I bleached alot of the coralline on the top of the rocks high up in the tank.
Im wondering now ... are there types of coralline that like different lighting intensities. If so, is it possible that most or all of mine is the low light variety since it was grown under VHO in the old system? If this is possible, how would I go about getting the coralline to grow in the higher light? Would it be worth rasing the halides even further seeing how I dont need the intensity right now? I can get the halides 2 1/2 feet above the water if need be. I could also screen the entire tank but Id rather not.

[Randy Holmes-Farley]

If the tank is not stocked and you are not feeding it or monitoring phosphate, it is possible that you have driven it too low. Excessively low nutrients can limit coralline growth.

[DarG]

<a href=showthread.php?s=&postid=11927751#post11927751 target=_blank>Originally posted</a> by Randy Holmes-Farley
If the tank is not stocked and you are not feeding it or monitoring phosphate, it is possible that you have driven it too low. Excessively low nutrients can limit coralline growth.

No, it's not stocked with corals yet. It is stocked with several fish and some shrimp and a small clean-up crew. Obviously the fish are being fed. Sorry if I didnt make that clear. I do routinely have to clean the glass of the normal slight algae film. I dont have a HA problem at all but there is obviously some bio-load with the fish, snails, hermits and shrimp. The last tank was a FOWLR under VHO lighting for a couple years before it was stocked with corals and I had a load of coralline within 6 months on that system before any corals were ever added, while it was a FOWLR for the first couple of years.

Like I stated, the Coralline is beginning to grow pretty well in the overflow that is screened over with 3 layers of fibergalss window screen. I screened it about 4 - 6 weeks ago and coralline began growing well there about 2 weeks after I screened. Mostly pink coralline I think, in the U tubes and on the walls and floor of the overflow boxes.

[Randy Holmes-Farley]

OK, if there is green algae then there are plenty of nutrients for coralline. Lighting seems likely then. :)

[DarG]

Thanks Randy. So, how do I get the higher light Coralline to start to grow? I know that Coralline will grow in halide lit tanks. Do I maybe need to get a piece of LR with good amount of Coralline from a halide lit tank?

[Randy Holmes-Farley]

Yes, that might be a good plan. Even some little rubble bits might be good enough, but the more you get the faster it can get going strongly.

[DarG]

Ok, Randy. Will do.

Thanks very much. BigE and everyone else as well. Thanks.

[Randy Holmes-Farley]

Let us know what you find happens!

Good luck. :)

[Boomer]

Just a note Dar

OK so does Coralline Algae grow on different surfaces by algae spores floating through the water before settling on the growing surface?

Yes and if they do not pass through the UV, which many will not, they will settle where ever in the tank and grow.


And if it does, wouldnt it end up going through the UV?

All of them will never go through the UV, only a percentage will. Many will settle before this happens.


And if so, does the UV kill Coralline algae spores?

It depends on the wattage, the "sap rate" and flow rate.

I know it kills other algae types, but does it for sure also kill coralline ?

Yes, if the wattage and flow rate is correct.