Best Molly for Algae Grazing

[ReefJedi]

On R2R and other forums some of the posts say mollies are good for algae grazing and some say they won't touch algae, but not a lot of the posts specify what kind of mollies they have and what algae they do or do not eat. Also, there are different opinions about how to acclimate mollies - some say toss it in for higher success rate and on the other end of the spectrum to drip acclimate over weeks, - but again, the posts aren't really clear about which kind of molly they had. Also, some posts say they can't handle high flow (which would be a problem in an SPS tank) but maybe some types can?

R2R, let's settle this! If you have experience with mollies in a SW tank, please answer:

1. Type of molly
2. Type of algae (and/or cyano, diatoms, etc.) they eat
3. Acclimation process and success rate
4. How long you've had the mollies in your tank so far
5. Amount/type of flow in your tank and whether they can handle it

 

[LiveWire]

I have black longfin mollies in my 30L frag tank to help with algae control. Mine were already saltwater acclimated to 1.018 and I just had to bring them up the rest of the way to 1.025. They are sold as feeders at the local shop but I threw them in my frag tank to help control a diatom issue that I was having. I would start with a handful and go from there. I did find that adding too many at once will just end in the strongest surviving. I actually feed mine every few days pellets as they seemed to like that better than flake. They are pooping machines but as long as they are grazing I'm alright with that. Hope this helps a bit.

1. Black Longfin Molly
2. They seem to eat a lot of different algae but not cyano
3. I purchased mine already acclimated @ ThatFishPlace
4. 3 months
5. If you get the flow too high they will struggle but they can handle a fair amount

 

[Bob Loblaw]

1. Standard Black Molly from Petsmart. Started with three. One died during acclimation. The other two fought until only one was left standing.
2. I've seen it nip at the seaweed clip but have never seen it grazing rocks or glass. Voracious eater of every frozen food offered.
3. Acclimated from fresh to full salt over about 4 hours.
4. A little over a year.
5. It's in an 8' tank with two MP40s at each end running at 100% Reef Crest or Tidal Swell- can't remember which. It seems to handle flow just fine.

 

[Halal Hotdog]

I had a few sailfin mollies and a pregnant dalmatian molly. They all got along well. IME they cannot handle high flow, really stresses them out and they stop coming out of the rock work. They can eat algae, but it is hit or miss. If they are being well fed they will most likely stop eating nuisance algae in your tank. In a softy tank with low flow I think they can do great. Their life expectancy is no where similar to most saltwater fish. They cannot handle aggression from other fish. It was an interesting experiment, but I would probably not do it again.

 

[Hermie]

1. Type of molly
2. Type of algae (and/or cyano, diatoms, etc.) they eat
3. Acclimation process and success rate
4. How long you've had the mollies in your tank so far
5. Amount/type of flow in your tank and whether they can handle it

1. sailfin, the larger the better. important to know the parents, not just a random LFS molly, but from a breeder
2. molly's mouths are "scraper" type mouths, so they prefer scraping algae off rocks in short bites. They do not have great "cutting" mouths, so they aren't great at cutting hair algae strands, however they can eat the base of the algae off the rock.
   
3. the scientifically validated acclimation process is brackish water for 24 hours and then move them into full marine. (half strength SW for brackish). this is a virtual 100% success rate, given that you are dealing with sailfin mollies.
4. in full saltwater over 6 months. in brackish, a year and a half.
5. I have 10x return flow and a 20x powerhead in my tank, which is a nano, so a lot of flow. They survive, but there are some challenges:
   I've had a small molly get stuck in the rocks when my powerhead was blasting the rocks, so I no longer blast my rocks with flow. I just adjust the flow to go over the rocks instead.
   Younger mollies can survive in high flow, it just makes them hungrier, which is good because it makes them want to eat more algae.

My tips:
Get young sailfin mollies, they will be able to "adjust" to the high flow as they develop, they will also be hungrier than adult mollies, they are also smaller so they can get into smaller cracks and crevices to eat algae. I would not recommend just going out and buying a random LFS molly and expect "peak" results, you want to get actual sailfin mollies, preferably raised in brackish or saltwater, in my opinion.

 

[Hermie]

Their life expectancy is no where similar to most saltwater fish. They cannot handle aggression from other fish.

I agree about not being an apex predator, but that can be said about a variety of species. I have an adult sailfin molly that bullies a puffer. If they got in a fight, I have no doubt that the puffer would win. I think aggression really depends on the individuals and the relative size of the fish. Sailfin mollies get bigger than a lot of gobies for example.

 

[eatbreakfast]

I've had P. sphenops and latipinna.

Sphenops ate algae better, latipinna handled flow better.

In too high of flow(sps reef with 2 powerheads and return) they hide in the rocks.

I've found they will eat filamentous hair algea. They will bite and tear bryopsis, but not eat it.

I've tried short acclimation(20min) and medium acclimation(2hours). 2 hour acclimation was more successful.

I never kept them beyond any algae issues. Once the algea was gone I got rid of them. If I wanted mollies I would just do freshwater.