Macroalgae tank newbie

[AquajunkieMD]

Like many in this forum, I am fascinated by the marine macroalgae. I have kept fish for over 40 years and reefs for at least a dozen. But this is my first effort at a macroalage based system. SO I could use some advice.

I have the benefit of living on the South Carolian coast so I can just run down to the inlet and pick up whatever the latest storm washed in. That makes it easy to find macros to try out. So this is, to some degree, an experiment. I would like to, if possible, use as many local algae species as possible.

But I am having two problems. First and foremost, most of what I harvest seems to slowly just melt away. That is likely the cause of the second problem, failure to attach. Obviously, this is related to the growing conditions in this tank (37 gallon. No skimmer and no filtration to speak of. I have 225 watts of VHO lighting on top with a set up reef spectrum. Some live rock and aragonite sand bed.) I also harvested some local oysters (easy enough to get around here) and added them to the tank. Only other occupants so far are a Tridacna clam which seems to be thriving, a couple of tube worms, two sea cucumbers, and a brittle star. No fish yet (although I am thinking seahorses and/or pipefish). Chemistry is good with almost no nitrate (likely a problem perhaps?) and no phosphate detected. Ph etc is OK. I do have an absolute boatload of gammarus. I mean TONS!!! Looks like a colony of sea monkeys in there! Any chance those little buggers are eating the algae faster then it is growing? I have noticed that they seem to swarm all over the sea lettuce so I am a bit suspicious.

So, any suggestions? I have a couple of thoughts, but I am new to macroalgae and would like some suggestions from those with more experience.

!. Could it be nothing more then the temperature in the tank? I keep it at about 78 degrees to accomodate the current occupants (which are tropical in origin after all). If that is the case, I suppose I will need to abandon my local searches (although most tropical Atlantic species of fish live off our coast so the local environment isn't THAT far off, which makes me think the local macros should do OK).

2. Could it be the gammerus? Do I need, then, just to go ahaed and get some kind of fish to chew them up until I am ready for the seahorses (I have a reef I can move that fish to later).

3. Wrong lighting? Seems least likely to me.

4. Is it a lack of supplements? Which ones? Or is it simply that, with no fish in the tank, there is so little nutrient input that the algae can't get what they need from the water column.

So, help!

Doug

 

[ClamIAm]

I'd definitely say temperature is your problem. I don't know what the water temps in South Carolina are but I'm willing to bet they are less than 78.

 

[Samala]

It might be temperature.. yes. But that isnt the only option. Consider for example that Caulerpa prolifera, one of the more widely distributed marine algae in the hobby, is quite happy in water temperatures from 62F to 86F (my own readings). It can adapt, so can a lot of other algaes.

I am curious what the size is of the peices you are collecting for culture. I find there is a certain critical mass needed for algae to survive when you find it beached or floating.

Keep in mind not all species of algae are benthic holdfasted species, some are happy just to float about for weeks if not months. Generally the algae in my tank is very hard to get to holdfast to a new spot. I have to cram it into a place I want it and pray the current doesnt sweep it out to the powerheads. The only foolproof method of holdfasting algae is to grow it directly on the substrate you want. That involves getting it to grow form its original spore, the seed.

Do you have any idea what the species are you have been attempting?

It is definitely possible for the amphipods to be consuming the macroalgae. I had trouble with them before and keep them out of my tanks. Some hermits and snails are also macro consumers.

I dont think the lighting is your problem, unless we wind back up with the heat issue. Then the amount of VHO could be contributing to the heat on the tank.

Still.. I wonder what species you are attempting, how much you colecting to try out, and what the bioload in this tank is like. If NO3 and PO4 are consistently reading zero, what lives in this tank?

I envy you on the oyster front. My latest project is a recreation of an partial oyster reef so I've been hunting shells down to create the look. One of the more tidal areas I visited last week had the oysters growing directly on red and black mangrove roots, it was pretty awesome looking.

>Sarah

 

[ClamIAm]

I guess I didn't realize that macroalgae that wide of a temperature range. Of course with the current Caulerpa taxifolia situation in the Mediterranean I guess that shouldn't be too surprising. Not having the ability to collect my own algae, I'd have to take Samala's advice on this one