macroalgae question

So i havent had time to get on here lately but the cogs in my head have still kept turning even though ive been overwhelmed with a ton of work lately.

so the question is I have a macroalgae growing, ulva i believe to be exact, and I was wondering is it safe to place this in my reef tank...You see I used to have a local collection tank with some smaller inhabitants from my local water source (the long island sound) but it has been running with no inhabitants other than a few macroalgaes that I've kept...The macros have been growing and have maintained very perfect green coloration and such and I was wondering would you think it is safe to move some into the fuge of my reef tank, the other tank has been empty for a few months other than the algae itself and maybe some local pods that my have survived for this long without having fish waste to feed off of

So what do you think is it safe or no and will it survive in the temperature change...I didnt use a heater in the local tank so it stays around room temperature ~68-75ish year round since I have central air and heating in the house, any insight at all would be appreciated

 

If it's from cooler water and you move it into a reef temps it will probably die off but it's worth a shot. If it does begin to die I'd get it out because as it decays it will release stored nutrients ie phosphorus.
Also if you have any herbivorous fish they will make quick work of the ulva.

 

Not sure I'd let anything from NY near my tankz, ya know theyre all greasy! Lol! Welcome back Bruno!

 

I would put a cheap heater in it and spend 2 weeks slowly raising the temperature until it is the same as your reef.

 

actually believe it or not I actually do have an inhabitant from NY in the tank....I have a baby horseshoe crab a little larger than a quarter which i've had for about 8months ....2 and a half to 3 months in my reef tank out of those 8....the local tank had a huge salt spike when I left my brother in charge of it and he was topping off with sea water not fresh lol smh but lesson learned i took control again and slowly stabalized my salinity over a 2 week period (yes i said 2 weeks....thats how bad it was spiked) and he was the only survivor so to make things easier I moved him into my main tank since they have been known to be placed in reef systems before and hes been doing great actually, he loves eating bristle worms and its funny to watch him surf around when the powerheads are on lol hes a funny little guy with a ton of character

Yes i know the NY collection laws and none were broken and the system was kept super clean

Back on subject though, The temperature in the local tank is ~72 right now and my reef tank is ~78 so I figure its not that big of a difference and I have plenty to spare so if I were to do it I'd probably just toss some in

and yes I have plenty of hermits plus a tang that would probably love it lol