Will My Fish Be Ok At Night?

I have a 5.5 heavily planted tank with a few small fish in it. I've heard that aquatic plants will release CO2 into the water during night due to lack of light, causing issues with the water chemistry and whatnot that could hurt fish.

My tank doesn't have a filter or air bubbles to stir things up very much and I'd rather keep it that way, since I don't have much space to spare for either. The ghost shrimp and snails have been living in there for a month prior to these fish and they've done fine, but I can't help but worry anyways. Will my fish be alright like this?

 

They should be fine. How heavily planted is it? If the whole tank is planted then I would at least add in an airstone or a really small sponge filter for water movement.

 

What kind of fish?

 

Here's a recent picture:




It's not as heavy as some that I've seen (the plants straight up blocked light 'cause their growth was so dense) but there's still a lot there.

The fish in question are ruby tetras.

 

if its so densely planted that water movement is inhibited, then you should probably get an airstone just to keep things moving. when people talk about surface disturbance to increase oxygen exchange, theyre actually meaning that to keep the oxygen concentration up then you need water circulation. the increase in surface area helps but its not as important as getting some flow going on in your tank

but as long as your temperature is consistent throughout your entire tank and it is stable then you should be fine

 

Your plants produce oxygen during the day and your filtration provides gas exchange. Honestly I wouldn't worry about it.

 

after seeing your picture I think you need to either remove a lot of the floating plants covering the surface and/or get an airstone.
you're blocking O2 exchange by covering a lot of the waters surface but other than that very nice tank

Your plants produce oxygen during the day and your filtration provides gas exchange. Honestly I wouldn't worry about it.

there is no filtration

 

there is no filtration

Is there anything providing flow at all?

I mean, people do Walstad tanks here without issue (dirt substrate, heavily planted with no filtration), I honestly don't think there's anything to worry about.

 

Is there anything providing flow at all?

I mean, people do Walstad tanks here without issue (dirt substrate, heavily planted with no filtration), I honestly don't think there's anything to worry about.

There isn't. I modeled this tank off of a series of videos that documented a walstad tank. Maybe I should make something that will keep a space from being overgrown with duckweed...

 

There isn't. I modeled this tank off of a series of videos that documented a walstad tank. Maybe I should make something that will keep a space from being overgrown with duckweed...

Foo the Flowerhorn? I love his video series. He inspired me to start a 3 gallon Walstad bowl several months ago.

 

Foo the Flowerhorn? I love his video series. He inspired me to start a 3 gallon Walstad bowl several months ago.

Yes, actually! I'm honestly a little surprised that the method he showed has worked so well for me, because up until now I have never been able to keep even a java fern alive, let alone have any aquatic plant flourish.

 

It's fine unless it's very hot. I lost fish in a heatwave but that was relentless heat for over three days.

 

We can agree or disagree on how op is keeping their fish. The short answer is no they will not run out of oxygen or be poisonined by co2 overnight provided the leveles get replenished during the day. Even a properly stocked unplanted tank can go around 24 with out power. So if op keeps the stocking low they will have no issues. That said some kind of water movement is beneficial by moving nutrients around as well as surface movement.

 

I'll consider adding an airstone eventually. I just don't have a spare pump or supplies and I'd rather not be spending money right now.

 

What about just a (very small) wave maker? One of those magnetic or suction cup ones that attaches to the aquarium glass. I think the idea is that in a Walstad tank the plants act as the filtration, similarly to how in a marine tank the live rock acts as the filtration. You really just need circulation.

 

What about just a (very small) wave maker? One of those magnetic or suction cup ones that attaches to the aquarium glass. I think the idea is that in a Walstad tank the plants act as the filtration, similarly to how in a marine tank the live rock acts as the filtration. You really just need circulation.

Do they make em that small? I don't exactly have a ton of space to work with here.

 

after seeing your picture I think you need to either remove a lot of the floating plants covering the surface and/or get an airstone.
you're blocking O2 exchange by covering a lot of the waters surface but other than that very nice tank



there is no filtration

The floating plants are key to the Walstad method (I was by chance actually reading her book this evening) removing too many floating plants could unbalance things.

Foo the Flowerhorn? I love his video series. He inspired me to start a 3 gallon Walstad bowl several months ago.

One of the best youtube channels IMO. The quality of his editing is amazing!

 

Do they make em that small? I don't exactly have a ton of space to work with here.

Okay so I just took a gander on Amazon and I can't find any wave makers that small, but I did find appropriately sized submersible pumps.

 

I found a few 80 gpg power heads too. Or even just a pump and air stone will slowly circulate water if room or astenics are an issue.

 

No filtration? How often do you change the water?

 

no idea about your question, sorry but I love the green in your tank! the long stuff on the left, is it anacharis? and are the tall ones in the middle a type of vals?

 

A small wooden air stone or regular air stone will help with circulation (the pumps can be very small and pretty cheap, the least expensive pump I have is one rated for a 20 gallon tank - shut off valves are useful for controlling flow - was 7$, I have six or seven of them - you will need a couple feet of airline tubing, the air pump at walmart has a check valve with it, the controlling valves are pretty cheap and very useful). As a walstad method I would just keep an eye on them for a while to see how they are doing to see if you need to implement something for oxygen.

 

No filtration? How often do you change the water?

Once a week, about 25-50% of it.

A small wooden air stone or regular air stone will help with circulation (the pumps can be very small and pretty cheap, the least expensive pump I have is one rated for a 20 gallon tank - shut off valves are useful for controlling flow - was 7$, I have six or seven of them - you will need a couple feet of airline tubing, the air pump at walmart has a check valve with it, the controlling valves are pretty cheap and very useful). As a walstad method I would just keep an eye on them for a while to see how they are doing to see if you need to implement something for oxygen.

okay. What are some signs that they might need some extra oxygen?

no idea about your question, sorry but I love the green in your tank! the long stuff on the left, is it anacharis? and are the tall ones in the middle a type of vals?

The stuff on the left is anacharis, the ones in the middle are corkscrew vals, and the plant on the right is water sprite. I even threw in some bonsaI rotala in there that was doing pretty awful in one of my other tanks, and they've rebounded wonderfully.

 

Heavy gasping (gills going wide along with heavy breathing), hanging out at the surface, lethargic (swimming slowly, acting off from their normal behavior).