Topic: What would be the best filter for aquarium Molly Fish? My mollies are in a 30 gallon Aquarium with gravel substrate. I’m new to keeping fish. Please don’t make fun of me for not knowing this. Thank for your help.

Awarded Answer:
Posted by Kelsey V: These fish are truly amazing creatures to keep as pets. I’m glad your researching topics like this because your working towards giving your animals an awesome home. Lets answer your question now.

Best Filter for Molly Fish Aquarium?

You do need a filter for your molly tank. The best filter for molly fish is really going to depend on what style tank setup you do. I prefer the aqua clear filters (go bigger than you need). The Aquaclear filters have been the best hang on back filters for a very long time. And you don’t have to continuously buy new filter pads! You just rinse the same one in your sink and put it back in. I highly advise them. Here is a picture and link:

As for food, I like omega one foods, frozen blood worm, brine shrimp and they also like veggies. I prefer sand for a substrate, pool filter sand to be exact. For tank mates that will depend on how big your aquarium is. A great addition to go with the mollies are cori cat fish. They are great to help clean up the extra food that falls to the bottom. The very first thing you want to research is how to cycle your aquarium. The basics are fill the tank with water and add prime water conditioner. After a few days add 2 fish. If you want mollies add 2 female (no need for a male for a while) Get a gravel vacuum and learn how to use it (it can be a challenge at first but you need to get the gunk off the bottom of the aquarium). Here is a pic and link:

Also, You need to change about 20-25% of the water weekly for the first 4-6 weeks. After that you can cut back on water changes but they are so important in the begining. Once the cycle is complete then add more fish SLOWLY (1-2 at a time) Cori cat fish would be my first add so you have the clean up crew started. I would not keep mollies in anything smaller than a 20 gallon if you want to raise babies… if you dont, dont get mollies lol! Hope that answered your questions.

I’m a newbie, so my tank is 2.5 gallons, no pumps, filter or heater. I do partial water changes once a week and there is one real plant in the back right corner. I feed tropical flakes once a day to my 2 Dalmatian mollies. I think the whiter one is pregnant, got a breeder box today and will put it in tomorrow. Pet store associate wanted me to buy bigger tank with ALL the gadgets and lots of plants. I just have this little tank at my desk at work. Now what? LOL!

I love dalmation mollies, my favorite kind! You definitely need a bigger tank, filter, and heater. At least 10 gallons. If you can’t do that try seeing if a local pet store or aquarium will take them on trade for a betta which is really the only fish you can (not really recommended still) keep in such a small aquarium with no filtration or heater.

Sadly a lot are taught just to make a sale. I’m an Aquatic Specialist at a pet store that has a 30 day guarantee on all fish so we actually have to make sure the fish is going to the proper home/set up or we lose money because the fish dies. Good luck to you 🙂 My recommendation would be a betta if you decide you want a desktop fish.

All around the Internet it says different things about what size aquarium to keep fish in. I had a 5.5 galling aquarium with several mollies in it for a long time and they did very well.

I had them in it for about a year and a half. They died because I gave them to my friend, and he didn’t take care of his tank.

You should get a 30 gallon minimum for the mollies.. when they reach 5 inches they need room. Anything smaller is not idea.

They grow slow, but they do… dalmation is just coloration.. those types of mollies get that large.

Ohh gosh mollys need heat and a bigger tank then that 🙁 suggest maybe a betta or a couple tiny neons which both need heat 2 thrive as well

Yeah, I take back my 4 – 5 inch.. male sailfins get 6 inches in size… yeah, people tend not to give them the size tank they need, the salt and so forth so they don’t live to full size.

Ya I found out with my black mollys they need salt or they’ll keep getting ick so I gave them away cause I was doin salt and it was killing my plants thinking of setting up a 30 with a few and doin salt treat ments and maybe work them to being salt water fish.

Bit of reading and research will help, Honey, but you definitely need to get those mollies out of that tank and into a MUCH larger tank before they die… only thing that can live in there without a filter is a betta fish – but they need a heater.

As people have said. Sailfin get towards the 6 inch mark. I would suggest a minimum of 30 gallons for these 2. They do however need a heater (25-28°C), filter and brackish water.

Sailfin mollies are not tropical fish. They are subtropical, and don’t need heaters. They can handle water temps. down to freezing. I know, because I keep them outside during winter with no heat, and they do fine. The mollies we buy in stores is bred from or is a hybrid of Mollies that are native to the USA from the Florida to the Texas coast + something else in order to make them MORE hardy. While a pinch of salt is a good thing, calling them brackish water fish is misleading. Fish that are truly brackish water fish do NOT do well in fresh water. Mollies do fine in fresh water, and will breed.

Okay. Thank you for your suggestions everyone. I think some of these employees at pet stores don’t know what they’re talking about. I got this aquarium and fish at the associates recommendation. Told her it was just for my desk and didn’t want anything that needed pumps and heaters. 30 gallons is too big for my desk. Thank you for your advice.

I’d return the fish, get some silk plants, a heater and filter, then proceed with a betta. Theyre funky dudes and as long as the tank is more than 2.5 gallons you’re able to keep one.

i have 4 old not working refrigerators as fish tanks, no filters, no pumps, no gadgets, i also have many real water plants. i seldom change water, 1 or 2 times every week. i feed them twice a day, before i go to work and after.

I need help! My older fish have these air bubbles all over! My white Molly has it the worst! I just recently had to replace my filter and pump but other than that there has been no change and no new fish to introduce ich I’m stumped! I don’t wanna lose her any suggestions?