Topic: What is the average growth size of molly fish? I have seen a lot of people saying they have 6 inch mollies? Do any of you have any pictures? That just seems really big to me? Thanks for your help.

*Awarded Answer
Posted by Jesse M: I’ve kept these fish effectively for years and have figured out what the best setups are for them to flourish. Mollies are beautiful vibrant fish that are super prolific. Let’s answer your question now.

How Large Do Molly Fish Grow?

Aquarium molly fish grow to around 2-3 inches in length. Make sure you give these fish adequate aquarium room to grow. The smaller the tank, the slower they may grow. Mollies also do a lot better in planted aquariums. Feed them once a day at minimum and you should see your molly fish grow to full size within a years amount of time. If you wish to have them grow faster, feed them more times a day.

The quality of food also plays a large role in the growth of your fish. We like to feed high quality foods because a person only spends a little more money. Do you want to be feeding your fish the “fast food McDonalds” foods of the industry? I didn’t think so. Here is one of our favorite brands Omega One Foods.

I’ve had this 55 gallon for about 2 months now. Got it for free with all the equipment. The fish were from my 20 gallon. I’ve been wanting to add more of a variety in the tank, but I can’t make a decision because I don’t want to regret anything. There’s 10 male guppies, a lonely molly fish, 3 small snails and 2 pictus catfish who are only active during the night when the lights are off.

I’m not new to the hobby, but I’m also not the best to get anything too hard to take care of. I am more interested in schools of small fish, but not too small that my catfish will try and make a meal with them. I don’t really want anymore Molly fish, but I know my catfish would appreciate the fry to snack on. I’m sure they miss that. 😂

Any suggestions?

Group of cory cats, cherry barbs, any tetras, gourami, you could pretty much put anything in there.

I agree with tetras. There is a huge variety, and they are very hardy. My peppermint tetras school really well, and they’re beautiful. I also love my silver-tipped tetras.

I agree with silver-tipped tetras. My favorite tetras thus far, specially when they are in abundance and schooling, plus how interactive they are when you run your hand or finger across the aquarium.

How many types of fish could I fit comfortably in this tank? Like, how many of each type would you suggest if I were to get tetras? Or a mixture of tetras and something else like swordtails or danios? I don’t want to overstock, but I also want a nice variety.

If you like rainbow fish and prefer small ones that will school, fork tail blue eyed rainbow, spotted blue eyed rainbow, or the red neon rainbow.

Personally since you have all those male guppies, I would buy some female guppies. Then I would look at other live bearer, tetras or danio.

Some tetras are fin nippers, so I’d be careful with the guppies. And others are too small (such as neons) and the catfish might eat them. I’d suggest peaceful gouramis, rainbows, and other fish that don’t grow too large unless they’re herbivores (but then, of course, you’d have to supply them with the adequate food). I have clown loaches that are pretty active and peaceful and don’t hide during the day. If you’re afraid of other fish eating the fry, then of course livebearers are not an option.

Size of Aquarium Mollies?

Any time I’ve had to move a molly to be on its own for any reason, she always gets stressed out. I’d recommend getting another, the pictus should be fine for fry control. And you might get lucky if you only have females. I had one female swordtail that never was pregnant until I introduced a male platy into her tank. (And now I have twinbar mickeys, which are adorable.) She’s like two years old now. Maybe a BN pleco. BN plecos are great.

Pictus cats known for picking off small fish so if you want small tetras or have baby guppies then the pictus will need to move.

I have no problem with fry being eaten. I used my catfish to keep my guppies from taking over the tank. I’m gonna steer clear of the smaller tetras for sure.

Hi all does anyone have any idea what’s wrong with my molly fish? He has a big lump on his side but it’s under the skin. Not sure what it could be or if he needs treatment? Xx thank you.

Looks like either tumor or internal parasite? How have his poops been? Parameters stable? No recent changes? How long has he had it? Eating habits changed? For now keep the water clean with small wc every few days and try adding some aquarium salt 1tbsp/5g.

He’s been pooing ok, parameters are good and stable. We have had some fish recently but currently no one else looking poorly. Thanks will do a water change tomorrow xx

if he’s eating fine and pooping fine and showing no other signs of ailments then it could very possibly be a fatty growth or tumor. Just keep the water clean. Parameters stable. And it can still live a normal life.

I’m very new to aquariums. My gf and I decided that it was something we’ve always been interested in

We have a 20gallon tank with now 3 molly fish and are wanting to add some platys soon.

We have a bio filter, bubbler and Heater. I keep the tank around 80 degrees.

My ammonia levels just seem to keep getting higher. I’ve been using Prime, and the water had got clearer and the nitrate levels are down to nothing. Does this mean the ammonia should get better soon? Or should I also be doing something else?

I have added aquarium salt and live bacteria. I do a 10% water change once a week and a 25% or so once a month.

I feed them once a day. Alternating between flakes and mini blood worms. Every few days I’ll add a small piece of blanched zucchini or peas.

I feel like the cycle has gone on longer than it normally should or what we were told. We’ve lost 2 mollies along the way 😞

Any advice welcome. Again we are new to aquariums!

Thanks

I think bigger water changes each week, I do 50% on my ten gallon every week. I do feed quite heavily with more fish, but 10 would feel like nothing to me. How long has tank been set up? How often do.you test? What are the actual levels for ammonia, nitrite, ph?

Tank has been set up for about 6-7 weeks, I forget the day we set it up. I test every 2-3 days. Ammonia was between 2-3 PPM yesterday.

Nitrates were severely high 2 weeks ago but in last check nitrite and nitrate were at 0 or just above. Could see just a small bit of colour on the strip.

Tank has been set up for about 6-7 weeks, I forget the day we set it up. I test every 2-3 days. Ammonia was between 2-3 PPM yesterday.

Nitrates were severely high 2 weeks ago but in last check nitrite and nitrate were at 0 or just above. Could see just a small bit of colour on the strip.

I did a fish in cycle two years ago, as I didn’t find out about the cycle part until I started. Had four platys. I had a spell of a few weeks where I had to test and change water everday. I was aiming to get ammonia and nitrites to below 0.25, so enough to feed bacteria, but safer for the fish. Do you know your ph because that has an affect on the tocicity of ammonia?

It could be that you need more biological filter media, or that the cycle has started all over again. Do you vacuum the gravel? If not then that gets bits of poop , food etc that is trapped and may be rotting causing ammonia. Also do you rinse out any sponges, padding etc as that will get rid of waste, but only in the discarded tank water, not tap water, unless it has been well dechlorinated, orherwise will kill your bacteria.

I do vacuum the gravel once a week. Maybe I should be doing more with my water changes.

I’ve been told to use the water from the change to clean the filter (not the bio wheel).

That filter is about 6 weeks old. I didn’t want to change it because the tank was in cycle.

Maybe I should put a new filter in? how often do you put a new filter in the tank?

Once all settled gravel vaccing once a week with your normal water change should be fine. At the moment though I would personally do bigger and more frequent water changes, getting the ammonia down, and using the prime inbetween to detoxify. As now having an ammonia spike that may be followed by another nitrite spike, so keep a close eye on that. Regards the filter I am not familiar with the wheel, as don’t tend to have them here in the Uk. I have internal cartridge filters, I replaced the cartridges with filter sponge and bio rings. I just rinse them, and as the sponge deteriorates add a bit more in. Gradually throwing away the bits that are falling apart. The aquarium co-op channel has a video on how to ” hot rod” filters to maximise the bacteria media, so I would look in to that before discarding anything. If get rid best to do in stages if you can. Quite often manufacturers recommend replacing cartridges etc too often, just to sell you more. Aquapros did some decent videos on the nitrogen cycle, if you go back a year or so.

Another question I would have to go along wit this would be how often do you clean and how often should i change my filter for a brand new one?

I know to never change the bio filter, but what about the main filter?

What is the filter model and what media is currently in it? How long has the tank been operating, and what are your water test readings? Once cycled, a good starting point for cleaning is 15-25% water change once a week, depending on your bio load. Cleaning of your filter depends on what is in it and what kind of filter. Do you gravel vac? If you don’t, you may be getting ammonia spikes from trapped waste and food debris within the gravel. Beyond that I need more info to help you. 🙂

This is what I fed 25 fish whilst on holiday!! 6 rainbows 6 molly 6 Tetra angel fish 6 platy. On a daily basis they get about twice this.

A tiny amount really

The more you feed the more they poop the more media you have to have

Show a photo in your hand of what you feed daily. A lot of beginner fish keepers keep on feeding. It’s fun.. but harmful to fish, and fish always hunt for food.

Get loads a real plants, and get some algae in the tank.. I only clean the front pane.. the algae is for the fish and the plants are for them too

I would def suggest making a media bottle. Air driven with a kilo of media- 1 litre of media. It will really help with any ammonia spikes.

Welcome to the hobby! There is some great advice in this thread. I would personally increase the frequency and size of your water changes until your cycle is complete, i.e. no more ammonia or nitrite. Now be warned that using prime, which is a great product can cause false readings from your test kit. Prime detoxifies ammonia, but that ammonia still stays in the tank, and will show up on your test kits.