Fluval Flex 15g Stocking

[Cole23]

Hi everyone! I’m new to Fishlore and fish keeping. I bought a Fluval Flex 15g and stand online a few hours ago, and I plan on doing a fishless cycle once it arrives and is set up and running. I haven’t decided if I will use live plants in it because I don’t know how capable the stock light is at growing plants, and also I don’t know anything about keeping live plants and it seems difficult. Anyway I have some stocking questions about this tank. The dimensions of the tank are 16” x 15” x 15” so I realize it’s limited length wise. So I found a 10 gallon stocking list on here made by Anders247 I believe, and I basically went by that. I got on Aqadvisor and entered the Fluval Flex 15 dimensions and it didn’t have the filter so I chose a HOB filter with a lower gph than the flex filter to be safe. I entered the following fish and got these results:

1 Honey Gourami
2 Male guppies
6 Pygmy Cory’s
6 dwarf rasbora or celestial pearl danio or ember tetra

Aquarium filtration capacity 155%
Water change 24% a week
Stocking level 89%

I’ve read a lot of people on here don’t trust Aqadvisor and some say the stocking level should be at 80% or lower. So I was hoping you all could tell me if this looks overstocked and if you would change the numbers of anything or have any ideas of other fish species that might be happier in my tank. I like colorful active fish, but I want to make sure the fish are healthy and stress free. Thanks!

 

[ProudPapa]

Welcome to the forum. I haven't kept them, but I've seen many people here say honey gouramis do better in groups. With that in mind, I'd probably bump it up to 3 of them and drop the guppies. I think the rest of it looks good.

 

[kansas]

I bought one of these tanks about 3 months ago. I went to the LFS asked the staff to suggest easy to grow plants.

I ended up with Jave Ferns, hornwort, a couple of crypts and some ludwigia. They've all grown really well.

I'm sure there a lot of plants that wouldn't do that well with that light, but it worked for me. I like live plants, I enjoy watching the fish swim through the plants and makes it easier to maintain a healthy tank.

 

[Cole23]

Hey everyone! So this is a post similar to my first post on Fishlore last week. I recently ordered a 15 gallon Fluval Flex, it will be here next week. I’ve read a lot about the nitrogen cycle and feel comfortable cycling my aquarium. One thing I’m not sure about is stocking this aquarium. I’m mainly interested in a combination of the following fish: honey gouramis, endlers, guppies, ember or ruby tetras, chili or phoenix rasboras, celestial pearl danios, pygmy cory cats, and Neocaridina shrimp. Obviously I’m not putting all of those fish in my tank just a very, very small combination of a few of them. Here’s why I’m so confused about stocking, I’ve been using AqAdvisor as a general guideline, I know a lot of people on here recommend not using it because it’s not accurate. But I entered a few random combinations of the fish listed above and got some odd results to me. So I entered my tank dimensions, added a HOB filter with a lower GPH than the Fluval Flex because the Flex’s filter was not listed, and I entered the following 6 celestial pearl danio, 6 ember tetra, 6 Pygmy cory’s, and 10 cherry shrimp. I got these results:

Filtration capacity 191%
Water change 19% per week
Stocking level 78%

Given I don’t plan on stocking that combination fish, it’s a just a random group I entered to try to understand stocking better. But those numbers seem low to me for 18 fish, and 10 shrimp in a small 15 gallon tank.The fish I listed above in the beginning of the post are what my wife and I are mainly interested in,
if anyone has a stocking suggestion for me using that list of fish please share me, this is a confusing topic for me. Also if anyone knows of any accurate way to calculate an aquarium stocking level that would be useful as well. Thanks for the help!!

 

[The_fishy]

You could probably get away with shrimp, the gourami, one of the schools in a group of 10 (more for chili), plus a snail or two.

 

[AquaticQueen]

The stocking plan would work just always double the water change percentage that Aqua Advisor gives you. So do 38% water changes in your tank weekly though personally I would go to 50%.

I might add a few more pygmys because that species only really thrive in groups of 10 or more.

 

[Cole23]

I’ve made multiple posts on this topic already but still feel a little lost. So I’ll be setting up a Fluval Flex 15 gallon next week, I know how to cycle it, but I do not know how to stock it. Going off the fish my wife and I are interested in I came up with a couple different combinations. The tank measures 16 x 15 x 15.

2 Male Guppies
6 Celestial Pearl Danio
6 Pygmy Cory’s
1 or 2 Amano Shrimp

Would something like that work in this tank? Please tell me if that is overstocked, I know very little about fish stocking. Other fish I’m interested in other than the ones listed above are honey gouramis, chili and phoenix rasbora, ember tetras, neocaridina shrimp and nerite snails. I’m just looking for a small combination of those fish, AqAdvisor doesn’t seem accurate, and the only information I can find on stocking lists and articles is how many of one individual species could fit in my tank, but as I’m looking to add multiple different fish to a community tank, that’s not helping me a ton. Any advice or suggestions are appreciated. Thanks!

 

[redmare]

I think just 2 guppies wouldn't be the happiest, it might make more sense to keep it to 1 top-schooling fish, and the pygmy cories

 

[FishGirl115]

I would do more guppies. They are extremely fun to watch. I have 6 in a 10g with 2 peppered corys rn.
2 might not be very happy. Might get lonely without more of their own kind

 

[ProudPapa]

If it was my tank I'd skip the guppies and bump the celestial pearl danios up to around 10, but this is your tank and not mine. If you like that stocking I don't see anything wrong with it.

 

[kanzekatores]

I would pick between the guppies and the CPDs and make a large/medium sized shoal of them.

 

[imba]

I would pick between the guppies and the CPDs and make a large/medium sized shoal of them.

for a 15g, i think this would be best. just stick with one type of mid-top dweller

 

[Cole23]

I have made a few posts recently about stocking my Fluval Flex 15 gallon, in one post I mentioned only having 2 male guppies in the tank along with some other peaceful fish. A couple Fishlore members expressed concern about only having 2 guppies in the tank because they might not be happy with that few of their own kind. I was hoping some of you that have experience with guppies could tell me the minimum acceptable number of them to have in a 15 gallon Fluval Flex and be happy? Also the same question for honey gourami? I was planning on just having one honey gourami in the tank but I don’t want to run into the same problem, and have a lonely, unhappy fish. Thanks!

 

[jinjerJOSH22]

Honeys are quite social, so at the very least 2 but ideally 3-5 or even more. If it was just Honeys in the tank i'd say get 5 but maybe dial it back if you're keeping others. As for gender ratio, as long as you have more females you should be fine however I wouldn't worry too much about males being overly aggressive

 

[Cole23]

Honeys are quite social, so at the very least 2 but ideally 3-5 or even more. If it was just Honeys in the tank i'd say get 5 but maybe dial it back if you're keeping others. As for gender ratio, as long as you have more females you should be fine however I wouldn't worry too much about males being overly aggressive

If I only purchased 2 honey gourami, would they both need to be female?

 

[jinjerJOSH22]

If I only purchased 2 honey gourami, would they both need to be female?

No, male/female would be fine. I would avoid purposely keeping 2 males but like I said they're not likely to cause too many issues together.

 

[kanzekatores]

I kept a honey gourami on it's own and it did quite well for a while, though I'd agree that they're way more active in groups. Aim for a pair. For guppies I would recommend at least three. They are social as well, and it also just looks better to have more colors rippling through the water.

 

[FishGirl115]

Yeah. I kept three guppies for a while then added more. Currently have 6.

 

[wishuponafish]

If you can't get female honeys and can only get males, it's better to have 1 or 3 than 2 because if you have 2, they can have a power dynamic where the stronger fish always bullies the weaker fish. They're more peaceful than other gouramis but can still get aggressive towards other males especially when they're in breeding mode.

 

[Cole23]

I’m still trying to figure out how I’m going to stock my Fluval Flex 15g. I was hoping to do something like:

2 honey gouramis
6 celestial pearl danios or other small schooling fish
6 pygmy cory

But I don’t know if it’s smart to try to fit 2 schools of fish in this tank that measures 16” x 15” x 15” so I was thinking of substituting the pygmy cories with some kind of Neocaridina shrimp. But I was concerned that the honey gourami might eat the shrimp. Have any of you ever housed small shrimp with honey gourami? And did the honey gourami ever eat the shrimp? I basically just want the bottom of the tank to have some sort of activity but if I don’t have enough room for a small school of cories, and the honey gourami might possibly eat the shrimp that I kept with them, then I don’t know what my options are. Any help is appreciated, thanks!

 

[jinjerJOSH22]

I’m still trying to figure out how I’m going to stock my Fluval Flex 15g. I was hoping to do something like:

2 honey gouramis
6 celestial pearl danios or other small schooling fish
6 pygmy cory

But I don’t know if it’s smart to try to fit 2 schools of fish in this tank that measures 16” x 15” x 15” so I was thinking of substituting the pygmy cories with some kind of Neocaridina shrimp. But I was concerned that the honey gourami might eat the shrimp. Have any of you ever housed small shrimp with honey gourami? And did the honey gourami ever eat the shrimp? I basically just want the bottom of the tank to have some sort of activity but if I don’t have enough room for a small school of cories, and the honey gourami might possibly eat the shrimp that I kept with them, then I don’t know what my options are. Any help is appreciated, thanks!

I'll preface this with I have very limited experience with keeping Cherry Shrimp and Honey's together as in I kept a single adult Cherry with 8 Honey Gourami in a 33 gallon tank.

I don't think you'll have too many issues with the Honeys but the Shrimp would likely do better without them, on the other hand i've heard that CPDs are quite good at hunting Shrimp.

 

[Cole23]

I’ve made quite a few posts asking about how to stock my Fluval Flex 15 gallon and got some great advice, I’ve put together a final stocking list that I want to go with but I’ve never had an aquarium so I wanted your opinions on this final list.

Tank info and dimensions: Fluval Flex 15 gallon
16” x 15” x 15”
Stock lighting
Stock pump
Fluval E100 heater
Fake plants in the back of tank
Bonsai driftwood tree with moss balls attached
Dragon stone
Moss balls
Extremely small smooth gravel about 2” deep
Temperature is set at 78 degrees
pH is 7.4

This is the stocking I would ideally like to go with:

2 honey gourami
3 male guppies
5 pygmy cories

I think these 3 species of fish are peaceful fish that are temperamentally, temperature, and pH compatible, but I might be wrong. Also I know most people recommend at least 6 cories but I thought with this tank being cube shaped and having less space length wise that it might be acceptable to keep 5.

Also I plan to cycle this aquarium using Tetra Safe Start Plus, I’ve read about it extensively including the thread where someone emailed Tetra directly with questions about Safe Start Plus. But if you have any suggestions on which fish to cycle with Tetra Safe Start Plus or any advice on using it please let me know.

Here is a picture of my tank, if you see any problems with my stocking list or the way my tank is set up please let me know how to fix it. Thanks.

P.S. - I realize my tank isn’t completely level, it’s off by a few millimeters, I ordered shims yesterday to put under the stand and am going to try to correct the problem.

 

[AquaticQueen]

I would add at least 2 more guppies or you will have aggression issues down the road and I wouldn't put pygmy corys in groups smaller than 10.
2 honeys (1m 1f)
5+ male guppies
10 pygmy corys

 

[FishGirl115]

I would go with 6-8 pygmy corys, 4 male guppies, and the 2 gourami

 

[Cole23]

You all don’t think that would be too many fish for this 15 gallon cube type tank? I know guppies have a higher bioload which is why I was trying to not have too many of them. I also want the fish to have plenty of room and not be stressed. I honestly don’t know much about the pump that came with my Fluval Flex, do you think it could handle that many fish?

 

[FishGirl115]

You all don’t think that would be too many fish for this 15 gallon cube type tank? I know guppies have a higher bioload which is why I was trying to not have too many of them. I also want the fish to have plenty of room and not be stressed. I honestly don’t know much about the pump that came with my Fluval Flex, do you think it could handle that many fish?

Hmm. Maybe cut guppies out? Or are you set on them?

Or just stick with your original plan. Honestly sounded pretty good to me.

 

[Cole23]

Hmm. Maybe cut guppies out? Or are you set on them?

I’m not necessarily set on anything other than the two honey gourami and pygmy cories, I like watching cories on the bottom. My wife loves the honey gourami, she also likes the large colorful tails of the male guppies but could probably live without them. I like Endlers, ember tetras, and other small schooling fish, I just didn’t know if putting another small school in with the honey gourami pair and school of pygmies would be over doing it for this tank, I definitely don’t want to be overstocked.

 

[FishGirl115]

I’m not necessarily set on anything other than the two honey gourami and pygmy cories, I like watching cories on the bottom. My wife loves the honey gourami, she also likes the large colorful tails of the male guppies but could probably live without them. I like Endlers, ember tetras, and other small schooling fish, I just didn’t know if putting another small school in with the honey gourami pair and school of pygmies would be over doing it for this tank, I definitely don’t want to be overstocked.

A thing I just read says the honeys do best with other active fish to hang out with... So maybe stick with original plan

 

[flyinGourami]

I would(personally) skip the gouramis since imo a 20 gallon is best and increase the numbers of guppies and corys.

 

[FishGirl115]

I would(personally) skip the gouramis since imo a 20 gallon is best and increase the numbers of guppies and corys.

That would be cool too. I love my colorful guppies.

 

[FinalFins]

I see no problem with a 15g that size with 2 honeys.

Personally I would go 2 honeys and a big school of microrasboras.

 

[AquaticQueen]

How about this?
2 honeys
5 Endler's
8-10 pygmy cory

 

[Cole23]

I see no problem with a 15g that size with 2 honeys.

Personally I would go 2 honeys and a big school of microrasboras.

Could I do 2 honeys, a school of Microrasboras and a school of pygmy cories? If yes, how many of each, and if no how many microrasboras would you do alone with the honeys? And are they fun to watch? I’ve read some fish species are shy, and hide.

How about this?
2 honeys
5 Endler's
8-10 pygmy cory

I’d be fine with that. Do you think my tank has enough room on the bottom for that many cories? It’s only 16” x 15” and I’ve got dragon stone in there taking up some space.

 

[AquaticQueen]

Could I do 2 honeys, a school of Microrasboras and a school of pygmy cories? If yes, how many of each, and if no how many microrasboras would you do alone with the honeys? And are they fun to watch? I’ve read some fish species are shy, and hide.

Yep, 2 honeys 7 micros and maybe 9 pygmys.

I’d be fine with that. Do you think my tank has enough room on the bottom for that many cories? It’s only 16” x 15” and I’ve got dragon stone in there taking up some space.

Pygmy corys aren't bottom feeders. They stick mostly to the middle of the tank. They also stay very small.

 

[Cole23]

I’ve made a few different posts about stocking my Fluval Flex 15, a lot of different people have given me great advice and suggestions, but since I’m new to fish keeping and don’t know much about stocking, I’m being indecisive and continue to change my mind. I’m trying to simplify things a bit although I will most likely have more questions in the future. So my Fluval Flex 15 measures 16” x 15” x 15” and I would like to know if I only stocked it with fancy male guppies and pygmy cories, how many of each would be appropriate? I’m not asking the maximum number of each I could have, I’m asking what would be the optimum number of guppies and pygmy cories to have to keep everyone happy and my tank not be completely or overstocked? My tank is not cycled but I’m going to start cycling my aquarium tonight with Dr. Tim’s ammonia. Thanks!

 

[FishGirl115]

I’ve made a few different posts about stocking my Fluval Flex 15, a lot of different people have given me great advice and suggestions, but since I’m new to fish keeping and don’t know much about stocking, I’m being indecisive and continue to change my mind. I’m trying to simplify things a bit although I will most likely have more questions in the future. So my Fluval Flex 15 measures 16” x 15” x 15” and I would like to know if I only stocked it with fancy male guppies and pygmy cories, how many of each would be appropriate? I’m not asking the maximum number of each I could have, I’m asking what would be the optimum number of guppies and pygmy cories to have to keep everyone happy and my tank not be completely or overstocked? My tank is not cycled but I’m going to start cycling my aquarium tonight with Dr. Tim’s ammonia. Thanks!

5-6 guppies
8 pygmy corys

 

[flyinGourami]

I’ve made a few different posts about stocking my Fluval Flex 15, a lot of different people have given me great advice and suggestions, but since I’m new to fish keeping and don’t know much about stocking, I’m being indecisive and continue to change my mind. I’m trying to simplify things a bit although I will most likely have more questions in the future. So my Fluval Flex 15 measures 16” x 15” x 15” and I would like to know if I only stocked it with fancy male guppies and pygmy cories, how many of each would be appropriate? I’m not asking the maximum number of each I could have, I’m asking what would be the optimum number of guppies and pygmy cories to have to keep everyone happy and my tank not be completely or overstocked? My tank is not cycled but I’m going to start cycling my aquarium tonight with Dr. Tim’s ammonia. Thanks!

I'm no stocking expert but I would go with 10 pygmys and 6-7 guppies. At most.

 

[Cole23]

I’m also slightly confused about bioload. I can’t find much information on fancy guppies bioload. I’ve read before that Livebearers have a high bioload, but I’ve also read on numerous different threads on Fishlore from multiple different people that male guppies have a low bioload. So which is it? And do some people consider Livebearers to have a high bioload because of how easy they are to breed and how many babies they have? Is that why Livebearers are considered to have a high bioload but some people say male guppies have a low bioload? All of the fish I’m interested in are appropriately sized for my aquarium but I’m finding differing information on bioload which is my main concern about stocking.

 

[flyinGourami]

I’m also slightly confused about bioload. I can’t find much information on fancy guppies bioload. I’ve read before that Livebearers have a high bioload, but I’ve also read on numerous different threads on Fishlore from multiple different people that male guppies have a low bioload. So which is it? And do some people consider Livebearers to have a high bioload because of how easy they are to breed and how many babies they have? Is that why Livebearers are considered to have a high bioload but some people say male guppies have a low bioload? All of the fish I’m interested in are appropriately sized for my aquarium but I’m finding differing information on bioload which is my main concern about stocking.

I wouldn't be too concerned. I have a guppy and his bio-load isn't a lot, most filters will be able to handle it. I would worry more about space, and if you stock based on that and have adequate filtration I really don't see it being an issue. If you get both females and males or females, they will very very likely reproduce, and that means higher bioload and less space. Feed appropriately of course.

 

[Kieren Munson-Burke]

5-6 guppies
8 pygmy corys

I think this would be ideal. Enough fish that everyone is able to socialize but not so much that the tank is overstocked! Pgymy cories are neat too because they don't stay only on the bottom, they will move around the whole tank some.

 

[Cole23]

Hey everyone, so this is probably my 10th stocking question thread since I got my first tank a few months ago, I apologize for posting so many. Anyway I have a Fluval Flex 15 gallon, 16” x 15” x 15”. I have an intank chamber one media basket in there with Seachem Matrix, Seachem Purigen, and filter floss, I also have the stock sponge with biomax and carbon. I plan on replacing the stock pump (132 gph) with the sicce syncra 1.0 (251 gph). Artificial plants, and around 10 moss balls. So my tank finished it’s fishless cycle 3 weeks ago and I stocked my tank with this:

6 male guppies
6 amano shrimp
3 mystery snails
Also 4 blue velvet shrimp, there were 8 of them but they arrived extremely young and tiny, and I think my guppies may have eaten some.

My question is can I add anything else to this tank or am I fully stocked? My guppies are active and swim in different areas of the tank but I wish I had some more fish and my tank was a little more active. Could I add more guppies? Or maybe a small school of pygmy or habrosus cories, I love cories. Ember tetra? I thought about adding a pair of honey gourami but wanted to ask you all first, also I’m not sure any online fish stores sells pairs of honey gourami. Basically if my tank isn’t fully stocked and I have room for more fish, what are my best options? And if it is fully stocked that’s fine and I’ll leave it like it is. Thanks for the help!

 

[FishGirl115]

You could do 8 pygmy corys and then you're stocked

 

[emilymg]

Hey everyone, so this is probably my 10th stocking question thread since I got my first tank a few months ago, I apologize for posting so many. Anyway I have a Fluval Flex 15 gallon, 16” x 15” x 15”. I have an intank chamber one media basket in there with Seachem Matrix, Seachem Purigen, and filter floss, I also have the stock sponge with biomax and carbon. I plan on replacing the stock pump (132 gph) with the sicce syncra 1.0 (251 gph). Artificial plants, and around 10 moss balls. So my tank finished it’s fishless cycle 3 weeks ago and I stocked my tank with this:

6 male guppies
6 amano shrimp
3 mystery snails
Also 4 blue velvet shrimp, there were 8 of them but they arrived extremely young and tiny, and I think my guppies may have eaten some.

My question is can I add anything else to this tank or am I fully stocked? My guppies are active and swim in different areas of the tank but I wish I had some more fish and my tank was a little more active. Could I add more guppies? Or maybe a small school of pygmy or habrosus cories, I love cories. Ember tetra? I thought about adding a pair of honey gourami but wanted to ask you all first, also I’m not sure any online fish stores sells pairs of honey gourami. Basically if my tank isn’t fully stocked and I have room for more fish, what are my best options? And if it is fully stocked that’s fine and I’ll leave it like it is. Thanks for the help!

I totally recommend checking on aqadvisor.com. It doesn’t use the misleading inch per gallon rule. You just have to select your tank size (filter if you want to.) I always play around with different stocking options as it lets you chose from about every species of fish out there, and the amount of them you want in your tank.

 

[Cole23]

I had checked on aqadvisor, I put in a few different combinations. One was:

6 guppies
6 pygmy cories
6 amano shrimp
3 mystery snails

So basically what I have now plus some pygmy cories and it had me at like 110% stocking level. So I got on here to ask everyone. That stocking combination didn’t seem unreasonable to me, but when I got back 110% I wanted to ask more experienced fish keepers for their advice on whether or not I could add more fish, and if so, what?

 

[julien0101]

6 guppies are fine in a 15 gallon if you do regular maintenance. If you want cories, you need to get six because they are a schooling fish. As a result, your stocking levels would be getting high.

if you really want more fish, I would recommend 1 ram cichlid. The species is a relatively peaceful one.

 

[emilymg]

I had checked on aqadvisor, I put in a few different combinations. One was:

6 guppies
6 pygmy cories
6 amano shrimp
3 mystery snails

So basically what I have now plus some pygmy cories and it had me at like 110% stocking level. So I got on here to ask everyone. That stocking combination didn’t seem unreasonable to me, but when I got back 110% I wanted to ask more experienced fish keepers for their advice on whether or not I could add more fish, and if so, what?

Is the tank heavily planted? I’ve heard people get away with adding more fish if there’s lots of plants. It would just also mean more maintenance for you.

 

[Cole23]

Is the tank heavily planted? I’ve heard people get away with adding more fish if there’s lots of plants. It would just also mean more maintenance for you.

No, it has artificial plants, and about 10 moss balls.

 

[emilymg]

No, it has artificial plants, and about 10 moss balls.

I checked aqadvisor and for a 15 gallon, the 6 guppies, 6 pygmy corys, 6 amano shrimp, and 3 mystery snails is only 92% stocked (if that’s what you were looking to do). A little on the higher side but with proper maintenance it should be fine. Also if you follow the right 1:2 M/F ratio for the guppies there will be less harmful territorial behavior.

 

[Cole23]

I checked aqadvisor and for a 15 gallon, the 6 guppies, 6 pygmy corys, 6 amano shrimp, and 3 mystery snails is only 92% stocked (if that’s what you were looking to do). A little on the higher side but with proper maintenance it should be fine. Also if you follow the right 1:2 M/F ratio for the guppies there will be less harmful territorial behavior.

I think that might be the results for a normal 15 gallon, the Fluval Flex is a cube shaped aquarium it measures 16” x 15” and 15”, and my results were 113% stocking level so I think I might be out of luck. Also all 6 of my guppies are male.

 

[emilymg]

I think that might be the results for a normal 15 gallon, the Fluval Flex is a cube shaped aquarium it measures 16” x 15” and 15”, and my results were 113% stocking level so I think I might be out of luck. Also all 6 of my guppies are male.

Ah yes you are probably right (I just used a standard 15 gallon). I think having 6 male guppies at that stocking level will cause them to be very territorial. Are there any other fish you are looking at getting? Or do the guppies need to be in this tank?