Smallest tank that can be reasonably cared for?

[Kehy]

Interested in opinions on this one. Describe the smallest tank you'd be willing to do with regular maintenance.

For me personally, I'm doing fine with a Mini Complete (about .3 gallons I believe), and I'm considering going just a hair smaller at .25 gallons (1 quart) or 1 liter. To be fair, those are about the same. What's stopping me right now is finding a small enough pump for that size. I've noticed my coral are doing fine in slightly cooler than normal water and don't appear to need heaters in their tanks. Lighting is another issue, but I've got a soldering iron and a tinkering side. It'd be fun to learn more.

This is still way bigger than the smallest freshwater stuff I've done though. My tiniest long-term project has been a 120ml bottle that's been going for 3 years. It'd be fun to have a matching tiny salt bottle to put with it, but I've given up on that dream.

 

[WIReefer]

Would love to see pictures of your tiny bottle freshwater tank.

 

[HuduVudu]

Sadly in salt water smaller is more difficult, and it seems that the difficulty is logrithmic with diminishing size.

 

[FloridaMicroReef]

Kehy! WOW! 0.3 gallons.

I thought I was small at a 3 gallon reefbowl. Interestingly, even my 3 gallon actually would be easier to care for if it was smaller. I have too much rockwork in it. And its too big to easily move to the sink. I do think an even smaller vase would be easier to maintain. A 1-2 gallon reefbowl would fit my light spread better.

The one thing that I do like about the three gallon tank and glass bowl, is that its large enough to maintain a stable temperature. Although this week, I turned the heater back on so the temp stays in the 76-78 degree range. I use an airstone for circulation. The fountain pump was heating the water to 82 degrees or hotter so I removed it.

Next to the 3 gallon reefbowl, I've had a separate jar acting as a totally secluded refugium for amphipod growth. That jar is much smaller = slightly less than a gallon. I do not have a heater for it. The cooler weather has that tank's temp dropped to 72.5 degrees.

Originally, the refugium jar was an even smaller old Betta fish bowl, or like the gold fish bowl you win at a carnival for throwing a ping-pong ball. That bowl held 36 ounces = 1 quart, 4 ounces. It was working fine. It used spillover light from the main 3 gallon tank.

I could see how a1 quart tank like that would work. You'd need the ambient air of the room to maintain temp. An interesting piece of live rock and some reject clippings of frags from a larger tank. It could easily look fantastic. Water changes are super easy. You can put the whole tank in the sink. Get a bucket of new salt water and siphon the new water down into the tiny tank. Letting the old and new water overflow the tiny tank and go down the drain. 1 gallon of salt water would let you changeover all the water in the tiny tank 4 times!

If Saltwater costs about $1-$2 to make, that's only 25 to 50 cents for a weekly water change.

 

[FloridaMicroReef]

That's called easy maintenance of your budget. Plus tiny coral frags quickly look substantial in a tiny tank. They don't get "lost" in the rockwork.

 

[Kehy]

Here's my little pico "palmtop" bottle.
This most recent pic is from Sept. 25th of this year (2020)

When it was first set up in April 14th, 2017

All the plants are there, accounted for, and too large to remove. This bottle has remained at my mother's house, despite me moving away. Pretty sure she hasn't moved it/doesn't know it's still sitting in the windowsill.

 

[Kehy]

As for what I'm thinking for 'a' pico (currently have a larger 3 gallon tank I need to do first).

I want to absolutely minimize the number of cords that have to be plugged into an outlet. I also want to keep everything as sealed as possible, going possibly as far as a locking lid. NO AIRSTONE, I HATE THOSE THINGS. Hardware and hardscape I want firmly secured in place, and unlikely to move. Why all this? I want a portable tank I can take to work in a bag. Also why not.

The electronics will have an external compartment with all the wiring and controller/timer bits, and I want everything fed from a single regular old cord. I'm an apprentice electrician, so tinkering with the bits is within the realm of things I might be able to figure out.

Given that I'm trying to use a minimum of power to keep things simple, I'd say a gallon is the largest size I'm willing to try with this idea. The heater is only 7.5 watts, so I don't want to go past what it can reasonably handle

 

[Andreas' Reef]

For saltwater it is 5 gallons

 

[Adamantium]

Interested in opinions on this one. Describe the smallest tank you'd be willing to do with regular maintenance.

For me personally, I'm doing fine with a Mini Complete (about .3 gallons I believe), and I'm considering going just a hair smaller at .25 gallons (1 quart) or 1 liter. To be fair, those are about the same. What's stopping me right now is finding a small enough pump for that size. I've noticed my coral are doing fine in slightly cooler than normal water and don't appear to need heaters in their tanks. Lighting is another issue, but I've got a soldering iron and a tinkering side. It'd be fun to learn more.

This is still way bigger than the smallest freshwater stuff I've done though. My tiniest long-term project has been a 120ml bottle that's been going for 3 years. It'd be fun to have a matching tiny salt bottle to put with it, but I've given up on that dream.

Out of curiosity, how do you handle top off in the Mini Complete Tank?

 

[Kehy]

Out of curiosity, how do you handle top off in the Mini Complete Tank?

Eye dropper and the larger tank sitting next to it/ bottle of distilled water. I cut a big window in the sump, so, among other things, I can clearly see water level.

 

[Kehy]

Here's the sump of my mini complete (mid water change). I decided I wanted a fuge mostly for the heck of it. I don't have the light (and I do have a mini grow light for it) on every day- usually every other night.

For saltwater it is 5 gallons

Why do you feel that this is the minimum size?

 

[andrewkw]

This tank was 8x6x8 this is about as small as I'd go. The problem when you get smaller, good luck finding a 1 watt heater, or an ato that fits in the back chamber, or even powerheads that wont look insanely big in it. You can potentially modify things to work and perhaps drill teeny tiny holes for some kind of closed loop but for that amount of effort you aren't going to get a great deal of return unless your goal is to have the smallest possible reef. The 2 gallon was big enough for small gobies, or inverts, a mix of corals and they could actually grow, at least initially.

 

[Andreas' Reef]

Here's the sump of my mini complete (mid water change). I decided I wanted a fuge mostly for the heck of it. I don't have the light (and I do have a mini grow light for it) on every day- usually every other night.

Why do you feel that this is the minimum size?

With fish/invertibrates, anything lower will be impossible to cycle and it will have ammonia spikes left right and center.

 

[Kehy]

With fish/invertibrates, anything lower will be impossible to cycle and it will have ammonia spikes left right and center.

Huh, funny, my 2 gallon has been set up over a year and is cycled.

Theoretically, if temp was maintained externally, it's really only water flow that limits size. Since this isn't an issue with freshwater, I could do pico/ palmtop setups. They certainly went through the cycling process and algae cycle, regardless of size, and did stabilize. Why would salt water be different?

I'm not considering ATOs, as they aren't strictly necessary in setups with a decent lid, although perhaps it would help reduce maintenance load. I see only pump, light, and heat as required equipment for a reef tank. Both light and heat can be provided externally, so that does help reduce required size

 

[Andreas' Reef]

Huh, funny, my 2 gallon has been set up over a year and is cycled.

Theoretically, if temp was maintained externally, it's really only water flow that limits size. Since this isn't an issue with freshwater, I could do pico/ palmtop setups. They certainly went through the cycling process and algae cycle, regardless of size, and did stabilize. Why would salt water be different?

I'm not considering ATOs, as they aren't strictly necessary in setups with a decent lid, although perhaps it would help reduce maintenance load. I see only pump, light, and heat as required equipment for a reef tank. Both light and heat can be provided externally, so that does help reduce required size

does your 2 gallon have fish?

 

[andrewkw]

Huh, funny, my 2 gallon has been set up over a year and is cycled.

does your 2 gallon have fish?

My 2 gallon was up for over 7 years and did have several different fish and inverts (those really tiny gobies don't tend to live more then a couple of years). Sexy shrimp lived their normal lifespan about 5 years or so.

 

[NeonRabbit221B]

I have a 1L jar I am sending to my sisters BF which is just aiptasia/snails/hermit with chaeto

My gf's mom is getting
Its sealed but about 300 mL and has a warranty.

 

[Kehy]

does your 2 gallon have fish?

Need to replace a giant solid piece of rock that basically takes up half the tank (it was my first salt tank, didn't know better). After that I'm thinking a microgoby, maybe a trimma.

Done it a fair amount in freshwater- but to be fair I also plant those like mad. For the record, in the freshwater world, Heterandria Formosa is the most fun you'll get in a tiny fish. Watching a half inch male trying to breed something literally x4 his size (and not his species) is amazing.

 

[just4plaay]

Seems like you need to find an alternative to a pump. Perhaps using an air pump outside the tank or if you want to try going really small and bare bottom maybe a magnetic mixer.

 

[Kehy]

Seems like you need to find an alternative to a pump. Perhaps using an air pump outside the tank or if you want to try going really small and bare bottom maybe a magnetic mixer.

I HATE airpumps. I also HATE airstones. I'll use a fountain pump and just direct the flow. Won't be random, no, but it can be adjusted to whatever direction as often as you want. They're also reasonably small, my smallest is around 1.5x1.75x1"