200l stocking idea

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Andy W89

Aquarium Advice Newbie
Joined
Apr 12, 2025
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6
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uk
Hi I'm looking for ideas to stock my 200l planted tank. It's an upgrade from my previous 60l tank and so far has 10 mollys in it.

Ao far I'm thinking:

10 mollys
2 firemouth cichlids or 2 opaline Gouramis
2 - 3 German blue rams

Can I fit in a few cori's?

what would you suggest to keep on top of algi?

Any other suggestions welcome 🙏
 
What are your water parameters like?

You are looking at fish that prefer different temperature ranges and different pH/ water hardness.

The mollys will prefer lower end of the tropical water range whereas the cichlids, and in particular the blue rams suit much warmer water. The rams really need to be in the 28 to 30c area.

Mollys are higher pH, hard water fish, whereas the gourami will prefer softer more acidic water.

You might find some overlap with the mollys and cichlids, having the water a little too warm for the mollys and a little too cool for the cichlids, but its not ideal. They will both do well in the same pH/ hardness range. If your water isn't too hard and higher pH the gourami might work with your mollys.

Corys will also prefer water on the softer more acidic side of the scale. Some corys will be good at the higher temperature, but generally they will do well at the same temperature as your mollys though.

Are you trying to build something around the mollys you already have, or are you wanting to look at building around one of the other species you mention?
 
What are your water parameters like?

You are looking at fish that prefer different temperature ranges and different pH/ water hardness.

The mollys will prefer lower end of the tropical water range whereas the cichlids, and in particular the blue rams suit much warmer water. The rams really need to be in the 28 to 30c area.

Mollys are higher pH, hard water fish, whereas the gourami will prefer softer more acidic water.

You might find some overlap with the mollys and cichlids, having the water a little too warm for the mollys and a little too cool for the cichlids, but its not ideal. They will both do well in the same pH/ hardness range. If your water isn't too hard and higher pH the gourami might work with your mollys.

Corys will also prefer water on the softer more acidic side of the scale. Some corys will be good at the higher temperature, but generally they will do well at the same temperature as your mollys though.

Are you trying to build something around the mollys you already have, or are you wanting to look at building around one of the other species you mention?
I'm looking to build around some thing new and a couple of larger center peice fish, I do like live bearers and the Mollys as a schooling group but I'm open to ideas.

I like the shape of the Cichlids.

The Cory's were only an idea to keep the bottom tidy and pick up un eaten food, and I have had them before.

My water is hard 120 kh ppm and 7.6 ph
 
Unless you plan on building everything around the blue rams with other fish that like the water really warm, I'd skip those. German Rams and their colour varients are better suited to softer, more acidic water too. Bolivian rams are a better option for lower water temperature and are more likely to do well in harder water with higher pH.

When people are talking about water hardness with regards to fish suitability, we are talking are general hardness (GH), not carbonate hardness (KH). While it's usually to find if ones high so is the other, this isn't always the case. While both are useful to know it's for different things. KH keeps your pH stable, GH is a more a measure of the mineral content in the water, specifically calcium and magnesium.

From the fish you have mentioned, and assuming your KH and GH are similar figures, about 6 or 7 degrees (slightly hard) i would say the mollys and cichlids are the most compatible with each other and would suit your water. You could do corys, bronze and peppered corys are usually better at adapting to harder, higher pH water.

As for an algae eater, again assuming the GH is in the slightly hard range, a small pleco or nerite snails?
 
I'm looking to build around some thing new and a couple of larger center peice fish, I do like live bearers and the Mollys as a schooling group but I'm open to ideas.

I like the shape of the Cichlids.

The Cory's were only an idea to keep the bottom tidy and pick up un eaten food, and I have had them before.

My water is hard 120 kh ppm and 7.6 ph
Best centrepiece fish= keyhole cichlids would definitely recommend them. Highly social and active species a nice group would be awesome in a 200l pair that with cories, mollies, your favourite shoaling fish(not to big) and a Bristlenose pleco( if you don’t want breeding keyholes) and it will be a great tank.
 
Unless you plan on building everything around the blue rams with other fish that like the water really warm, I'd skip those. German Rams and their colour varients are better suited to softer, more acidic water too. Bolivian rams are a better option for lower water temperature and are more likely to do well in harder water with higher pH.

When people are talking about water hardness with regards to fish suitability, we are talking are general hardness (GH), not carbonate hardness (KH). While it's usually to find if ones high so is the other, this isn't always the case. While both are useful to know it's for different things. KH keeps your pH stable, GH is a more a measure of the mineral content in the water, specifically calcium and magnesium.

From the fish you have mentioned, and assuming your KH and GH are similar figures, about 6 or 7 degrees (slightly hard) i would say the mollys and cichlids are the most compatible with each other and would suit your water. You could do corys, bronze and peppered corys are usually better at adapting to harder, higher pH water.

As for an algae eater, again assuming the GH is in the slightly hard range, a small pleco or nerite snails?
Thanks for the advice, I think I will avoid the blue rams in that case and may be look at Bolivian instead?
 
Best centrepiece fish= keyhole cichlids would definitely recommend them. Highly social and active species a nice group would be awesome in a 200l pair that with cories, mollies, your favourite shoaling fish(not to big) and a Bristlenose pleco( if you don’t want breeding keyholes) and it will be a great tank.
Hi thanks, I have considered Keyholes but I was told that I could go for Firemouths which i prefer as they are more colourful. However I'm now nervous they will be to aggressive so back on the fence with the keyholes.

I'm not a fan of Pleco's either
 
Hi thanks, I have considered Keyholes but I was told that I could go for Firemouths which i prefer as they are more colourful. However I'm now nervous they will be to aggressive so back on the fence with the keyholes.

I'm not a fan of Pleco's either
Firemouths are beautiful fish and not too aggressive from what I’ve heard and can be kept with swordtails and mollies but no planted community tank with them. I would choose your main fish you want to choose stocking on as, you could go with firemouths and mollies and maybe a bottom dweller maybe a catfish with it. Or community tank, with a cichlid centrepiece fish or maybe 2(3 at a stretch if singles). For example 2 keyholes with a single EBA or angelfish. Add cories, mollies and maybe a shoaling fish( larger if with an electric blue acara or anglefish) . :)
 
Firemouths are beautiful fish and not too aggressive from what I’ve heard and can be kept with swordtails and mollies but no planted community tank with them. I would choose your main fish you want to choose stocking on as, you could go with firemouths and mollies and maybe a bottom dweller maybe a catfish with it. Or community tank, with a cichlid centrepiece fish or maybe 2(3 at a stretch if singles). For example 2 keyholes with a single EBA or angelfish. Add cories, mollies and maybe a shoaling fish( larger if with an electric blue acara or anglefish) . :)
Thanks, I think I will go with the firemouth option, do you suggest getting a pair?
 
If you want breeding yes or you could maybe do 3/4 if you want. Then with mollies, maybe a larger shoaling fish(maybe skip) and a catfish that would be nice.
Cool thought that i might have been my limit due to size. Have you got s suggestion for the shoaling fish, thinking Maybe Harlequin rasboras, cherry barbs or lemon tetras and how many could I fit with:

10 mollys (I aalreadyhave these)
2 Firemouths

As for the catfish I'm not a fan of pleco's and have been told Cory's won't be suitable.
 
Cool thought that i might have been my limit due to size. Have you got s suggestion for the shoaling fish, thinking Maybe Harlequin rasboras, cherry barbs or lemon tetras and how many could I fit with:

10 mollys (I aalreadyhave these)
2 Firemouths

As for the catfish I'm not a fan of pleco's and have been told Cory's won't be suitable.
There are other catfish you can add like an upside down catfish or many others but if you don’t want one you don’t have to. I think out of the shoaling fish you suggested lemon tetras are probably the best option and I would get 8-10.
 
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