Walstad tank stocking

[Madmaxoo7]

I am a beginner and have a 15 gallon high tank(20"x10"x18") with plants like dwarf hair grass, anubias nana petite, ludwigia super red, Bacopa caroliniana & a few water lettuce. There are 6 widow tetras, 5 cherry shrimps & 1 spotted nerite snail. They have all been doing fine for about a month now. I really would like to add some chilli rasboras. Is it possible? If so, how many should I add? Please point out mistakes & give suggestions since I m new to fish keeping.

 

[GaryE]

If you are going Walstad, you are overstocked. The system only works with very low stocking. Widow tetras would demolish chili rasboras in a 15 high. The tetras get surprisingly big in time, and can be rough. It's not my favourite species - lose them and get the chilis as a lower bioload, prettier fish.

Always remember to plan for success. The widow tetras may be great now, but they grow. Chilis stay small.

 

[Madmaxoo7]

Thanks a lot for the tip. I regret not buying neon tetras instead of the widows. Can chillis be kept with neons? I will add in a filter if required. Can u plz tell how many from each of these 2 species I coould keep in this particular tank with and without a filter.

 

[WhistlingBadger]

A 15 high is too small for neons too, IMO. They're small but very active. I agree with Gary--If it were me, I'd ditch the widows and get a school of chilis. Adding a filter wouldn't really matter. It's a question of their needing more space to swim.

If you can find homes for the tetras, you could get a nice school of micro-rasboras instead. Chilis look GREAT in a heavily-planted, Walstad tank.

 

[Madmaxoo7]

Ok I guess no tetras for me then. Is there any chance I can keep any 2 types of fish to bring about a contrast. What about one honey gourami and a few chillis Or 3 guppies and a few chillies. Plz forgive me if I sound too outlandish.

 

[WhistlingBadger]

No need to apologize--it's good to kick around ideas, and you've come to the right place for advice. The basic rule is that small tanks need small, not-too-active fish. And with most fish, what matters is the footprint (size of the base) more than the total gallons.

Since a 15 gallon high has basically the same footprint as a 10 gallon, you're fairly limited, but there are some cool options. I've never kept honey gouramis, but seriouslyfish (my most trusted source) recommends a bigger tank for them. Since Walstad tanks need to be under-stocked, I would advise against them. Guppies might work. @emeraldking is one of our resident guppy experts, so perhaps he can comment on that. But a 15g is really quite a small tank, so don't be afraid to think small. One nice school of microrasboras (there are many different kinds) and a few shrimp and/or snails would look beautiful.

To my way of thinking, animals like snails and amano shrimp don't add much bioload because you don't feed them much; they simply eat what's already there. So you could add a few shrimp or snails easily enough.

Aqadvisor.com is good resource for playing with ideas. It isn't perfect, but it will at least keep you from getting overstocked.

 

[Byron]

There are some suitable fish, but being "nano" they have more need of suitable water parameters, especially the hardness (GH). If you can give us the GH and pH of your tap water?

 

[Archerfish]

I am a beginner and have a 15 gallon high tank(20"x10"x18") with plants like dwarf hair grass, anubias nana petite, ludwigia super red, Bacopa caroliniana & a few water lettuce. There are 6 widow tetras, 5 cherry shrimps & 1 spotted nerite snail. They have all been doing fine for about a month now. I really would like to add some chilli rasboras. Is it possible? If so, how many should I add? Please point out mistakes & give suggestions since I m new to fish keeping.

Mistakes? Ha! We have all made them and continue to make them! I am a Walstad kind of aquarist. Visitors have said, "'Look at those pretty plants! Are those real? Whoa, there are beautiful little fish in there!" You might consider Celestial Peral Danio (Galaxy raspora) as a complete replacement. They are simply gorgeous and tend to hover in the lower part of the tank and produce the 'Wow' effect.

 

[Sgooosh]

I recommend boraras and microrasboras too, they don't get as large as their normal rasbora counterparts

 

[Madmaxoo7]

There are some suitable fish, but being "nano" they have more need of suitable water parameters, especially the hardness (GH). If you can give us the GH and pH of your tap water?

I use RO water because my tap water is very hard and ph is below 7.

 

[GaryE]

Walstad set ups come at a high cost, and not in money, An unfiltered stagnant plant tank of 15 gallons will hold 6 chili rasbora sized fish and nothing else. The fish is very small as a response to it coming from natural walstad conditions - swamps. Guppies come from streams, and like more oxygen than a walstad offers.

You have chosen a specialized aquarium set up, and you can't stock it like a standard tank.

 

[WhistlingBadger]

I hate to contradict Gary, but Walstad tanks aren't stagnant. They usually contain a small water pump or sponge filter to move the water around. The the plants and substrate do provide excellent filtration if you set them up right. But they do need to be stocked thinly.

 

[GaryE]

I'm happy to be contradicted.

My understanding from the OP is that there is nothing mechanical in the set up in question. With all due respect to @Madmaxoo7 , I see a tank in what may be a warm climate, if it's southern India, and a new aquarist. Probably, no heater is needed. There's no mention of aeration.
The word Walstad gets thrown around a lot, but most Walstad set ups I've read about didn't follow Walstad's works. It's quite a thing for a new aquarist to take on. If, @Madmaxoo7 , you have read her book and done everything by it, then you are an advanced aquarist as of day one. Most people I've read call an unfiltered tank with a lot of plants a Walstad set up.

 

[Madmaxoo7]

I do have a small sponge filter. I always thought walstad tank do not need filters but kept it anyway just to be safe. @GaryE No I haven't read the book, I just followed steps from a walstad tank setup video from Foo the flowerhorn YouTube channel. I checked my current stock level with the widow tetras in aqadvisor.com and it is 80%. What is the required stock level?
Btw @GaryE , your guess was right, I am from south India. How did you know?

 

[emeraldking]

Guppies will do fine in a 15g tank. Just pay attention on their ability to reproduce massively.