Macroalgae melting

[Critter Doc]

My macroalgae had been doing great (it was at least triple its original size) but has been looking pale in the last couple of weeks and is now definitely shrinking. Water parameters are all good and I have not lost any shrimp or snails. The tank is a little 5-gallon hex. I also have one of Mustafa's moss balls and a small clump of Süßwassertang in there; would those be enough to rob the macroalgae of nutrients?

[Varanus]

It seems that partially disintegrating for no apparent reason and then rebounding later is something that the macroalgae often does. Mine did much the same as yours, and the fragments proceeded to start growing like crazy later. If the shrimp are fine then I wouldn't worry.

[Critter Doc]

That's interesting! I tried to move it today and it completely fell apart into individual strands - actually had to turn on the filter to clear them from the water. Is there still hope of its resurrecting itself?

[Varanus]

I don't see why it wouldn't.

[KenCotigirl]

The algae Looking pale can be caused By too much or too intense light. Have you changed your lighting? I do not believe the Süßwassertang is meant for brackish water. I would remove it. Send us a few pictures.

KenP

[Critter Doc]

Ken, the light is from a two-year-old fluorescent bulb - it's actually quite dim. And the Süßwassertang came with the Opae'ula I got from a local breeder; he'd adapted it to brackish and it's been thriving - growing slowly, for sure, but not showing any signs of melting.

[Mustafa]

Hey there! You're already getting lots of good answers here. As for the Sueswassertang....trust me...it's not growing *at all*. It can't be "acclimated" to brackish conditions..heck, it doesn't even do well in really hard, alkaline freshwater.

It's basically dead while remaining green in your tank. That plant has an amazing ability to stay green (even longer than Java moss!) while basically dead or dying. It doesn't really melt like other plants...even in marine tanks! (yes..I tested it under various salinities). I would take it out.

[Critter Doc]

Hmm. I compared it with pictures from when I first put it into the tank and it's definitely bigger - awfully vibrant looking for something that's dead. But if there's a chance it's why my macroalgae fell apart, I'll take it out. No reason it can't sit in a jar in my windowsill.

[Mustafa]

Hmm. I compared it with pictures from when I first put it into the tank and it's definitely bigger - awfully vibrant looking for something that's dead. But if there's a chance it's why my macroalgae fell apart, I'll take it out. No reason it can't sit in a jar in my windowsill.

Yes, it's vibrant green but dead/dying if it is really *Suesswassertang*. As I said...that's a "feature" of it. That's what makes some plants deceptive...Java Moss and to a certain extent Java fern have some of that ability too in saltwater...but Suesswassertang even more so. Can you post pictures of your Suesswassertang? Preferably "before" and "after" pictures. I'm 99.99999% sure that there can't be any growth at Supershrimp salinities, unless the "breeder" (I'm having my doubts now after he/she told you Suesswassertang thrives in his/her tanks...and other info you shared he/she gave you...there are after all lots of people that claim to be breeding these shrimp but they actually don't and just get them from Hawaii.). Talking about salinity...what is yours? Did you measure it? If not...how did you prepare your water (i.e. how much salt did you use in relation to water?).

Yes, just put it in a jar by itself...and tell us if it grows at all in freshwater again..probably not, but you never know.

[Ace]

Yeah, photos. We want photos.

[Critter Doc]

I use Instant Ocean - a little less than 1.5 cups in 5 gallons of RO water gives me a SG of around 1.012/salinity just under 20. It's checked with a refractometer whenever I do a water change or top up with RO.

Looked through my photos and realized I don't have a good "before" comparison pic, just a shot of the loose clump from when I got my Opae'ula:

And a more recent pic of the Süßwassertang (it's tied to an inert rock) just before I took it out:

And just for fun, Opae'ula yoga:

[Mustafa]

I like the "yoga" picture. Thanks for the pics! From the pictures it actually looks like the normal "roundish" growing tips of the suesswassertang have decayed, so it's definitely not growing. Given that some of those tips are still there in the first picture it's highly likely that that clump either comes from freshwater, or the "breeder" just recently put a large clump into a supershrimp/opae tank and decided that it's "growing." Either way you were provided with misinformation.

I also don't see it being any bigger than the initial clump. Either way, now we know it's suesswassertang and we know your salinity and unless some miracle of nature caused a mutation (highly unlikely given the number of reports of freshwater plants "growing" and "surviving" in high salinity brackish invariably turning out being 100% wrong over the last 13 years or so), it's simply dead or dying unfortunately.

[Ace]

So sad!

[Critter Doc]

Eh, not a big deal, Ace - my shrimp are happy, the snails are doing their thing and the plant is now residing in a little jar on my windowsill.

[Mustafa]

Any updates?