Help Me Stock! 30g Planted w/ Cardinals

[Gemtrox42]

Background: 30 gal tank, lightly planted with gravel bottom, mostly hornwort, swords and java ferns, lots of driftwood. The top of my tank is nearly completely covered in duckweed. My fish are 13 cardinals, 5 pygmy corys and cherry shrimp, as well as mixed snails including assassins Water is 78 degrees, hang on back filter so should be well oxygenated. Water parameters are 7.3 pH, ammonia 0, nitrites 0, nitrates 5, GH 10 dGH, KH 100-120.

I recently rehomed my main residents so now I am left decently understocked. I would like a few more cardinals to make a nice sized shoal, but they spend the majority of their time in the middle, leaving the top rather barren (and if I rehome the cories, the bottom as well). So given the parameters and compatibility with cardinals, I was looking for something to occupy the top and bottom, and I was leaning towards dwarf gourami. But any suggestion or input is welcome!

And if it helps, here's what I'd be willing to change (off the top of my head) to accommodate new fish: rehoming cories and shrimp, increasing the number of plants, removing or reducing the duckweed on the surface.

 

[OliveFish05]

Hi! I am not great with stocking, but since being here I have learned

1. Cories need sand! If you can't switch from gravel to sand, rehoming the cories could be a good option, in which case maybe a pleco to occupy the bottom?
2. Gourami loveeeeee floating plants, and i am sure would greatly benefit from all the duckweeed! Gourami like slower water water, is your filter's flow adjustable? Or not too strong to begin with?

 

[Essjay]

Dwarf gouramis come with health problems - those fish bred in the far east are often infected with one, sometimes two incurable diseases by the time they reach the store. If you can find a local breeder they would be OK but if not I would avoid dwarf gouramis.
Honey gouramis are a bit smaller but they don't have the same health issues.

 

[MammaBearinTN]

I don't have cardinal tetras, but I do have ember tetras with honey gouramis and a pair of german blue rams. I also have corys, but they're on a sand substrate. The honey gouramis are much more interesting in a shoal. I have seven.

 

[Gemtrox42]

Hi! I am not great with stocking, but since being here I have learned

1. Cories need sand! If you can't switch from gravel to sand, rehoming the cories could be a good option, in which case maybe a pleco to occupy the bottom?
2. Gourami loveeeeee floating plants, and i am sure would greatly benefit from all the duckweeed! Gourami like slower water water, is your filter's flow adjustable? Or not too strong to begin with?

I'm planning on rehoming the cories for sure. Any particular pleco recommendations?

And I know that gourami like floating plants, but as of now my duckweed covers 98% of the tank surface. Since they need to breathe air, I'm assuming that's too much, right?

I've heard that both cardinals and gourami like slower water. Currently I am using an Aqueon QuietFlow 20 HOB filter. Is that too strong? If so, what would work better?

 

[Gemtrox42]

Dwarf gouramis come with health problems - those fish bred in the far east are often infected with one, sometimes two incurable diseases by the time they reach the store. If you can find a local breeder they would be OK but if not I would avoid dwarf gouramis.
Honey gouramis are a bit smaller but they don't have the same health issues.

That's a shame, I hadn't heard that before, and they are the most beautiful tropical fish I've seen! Other than honeys, is there anything else that comes to mind for the top or bottom?

 

[Essjay]

Do you want a single/pair of fish or would a shoaling fish be OK?

When I had dwarf pencilfish a few years ago, they swam in the top half of the tank

Nannostomus marginatus – Dwarf Pencilfish (Nannostomus marginatus picturatus) — Seriously Fish

www.seriouslyfish.com

 

[Gemtrox42]

Do you want a single/pair of fish or would a shoaling fish be OK?

When I had dwarf pencilfish a few years ago, they swam in the top half of the tank

Nannostomus marginatus – Dwarf Pencilfish (Nannostomus marginatus picturatus) — Seriously Fish

www.seriouslyfish.com

I'm open to either, as long as they don't eat my cardinals!

I've heard of pencilfish, but can't remember seeing them before. They look like Danios, but more colorful. I'll look into them, thanks!

 

[OliveFish05]

I'm planning on rehoming the cories for sure. Any particular pleco recommendations?

A bristlenose pleco could do well! They come in brown, albino, lemon, starlight, and super red varieties. You can even get long finned!

And I know that gourami like floating plants, but as of now my duckweed covers 98% of the tank surface. Since they need to breathe air, I'm assuming that's too much, right?

Hmmmm. I have seen people take silicone rings or small lengths of airline tubing (curved into a round hoop almost) and then laid on the surface, then all the floating plants pulled out of the inside of the circle, to leave open spots on the surface, perhaps you could try that to allow an area for the gourami to breathe?

I've heard that both cardinals and gourami like slower water. Currently I am using an Aqueon QuietFlow 20 HOB filter. Is that too strong? If so, what would work better?

I don't have any experience with that filter, but I would assume as long as it is not blasting all over the tank it should be fine. I think just a gentle flow is good

 

[Gemtrox42]

A bristlenose pleco could do well! They come in brown, albino, lemon, starlight, and super red varieties. You can even get long finned!

They seem to have higher GH requirements than I can provide. My water is 12 dGH and I'm reading they need 20 minimum. Does that sound right?

Hmmmm. I have seen people take silicone rings or small lengths of airline tubing (curved into a round hoop almost) and then laid on the surface, then all the floating plants pulled out of the inside of the circle, to leave open spots on the surface, perhaps you could try that to allow an area for the gourami to breathe?

Thanks, I had been using a similar method but I must've cut the tubing too short. Will buy more and try again.

I don't have any experience with that filter, but I would assume as long as it is not blasting all over the tank it should be fine. I think just a gentle flow is good

It's not blasty over a large area per se, but it creates a pretty strong column of water. There isn't a lot of readily available info I can find matching flow rate to certain filters, so I guess I'll have to keep looking.

 

[finfayce]

Hi! I am not great with stocking, but since being here I have learned

1. Cories need sand! If you can't switch from gravel to sand, rehoming the cories could be a good option, in which case maybe a pleco to occupy the bottom?
2. Gourami loveeeeee floating plants, and i am sure would greatly benefit from all the duckweeed! Gourami like slower water water, is your filter's flow adjustable? Or not too strong to begin with?

hi thanks for your comments.i have 3 small catfish (cory)arriving tuesday. i need more gravel in my 20 gallon guppy tank. should i get sand instead?

 

[OliveFish05]

hi thanks for your comments.i have 3 small catfish (cory)arriving tuesday. i need more gravel in my 20 gallon guppy tank. should i get sand instead?

I have heard Cories prefer sand to gravel, the gravel can damage their little whiskery things. I have also heard Cories filter the sand to eat, making it a necessity. If you can, I would highly recommend getting a larger school of Cories, as they find safety and comfort in numbers!

 

[finfayce]

thank you i will have 4 cories altogether. other members have said carbon doesn’t do much after a day or 2. i have a new Fluval with 3 cartridges. 2 sponge / 1 some kind of white fiber. ( the proper names escapes me - i’m old lol)

 

[finfayce]

what kind of sand should i buy? looking online there are sands for saltwater and freshwater water, for cichlids etc.
i also have 2 plecos. i was told they add a lot of poo but they seed to keep the ceramic decorations clean.

 

[OliveFish05]

what kind of sand should i buy? looking online there are sands for saltwater and freshwater water, for cichlids etc.
i also have 2 plecos. i was told they add a lot of poo but they seed to keep the ceramic decorations clean.

I recommend Quikrete play or pool filter sand, 50 lbs bags. Or, Caribsea is A good brand