Thoughts on Heater Free Aquaria

[Uberhoust]

The Cichlid entry, https://www.fishbase.se/summary/69375, by @I Like Rare Fish brings something of interest to me and I expect others as well. And that is, is it possible to have an interesting cold water tank and save a bunch of power.

Right now I mostly care about angel fish, since getting them a few years ago they have been very interesting to raise, primarily because they interact with me, seem intelligent, and I have the conditions that make raising them easy.

The problem with tropical fish is, they are tropical. A 300 watt heater is the minimum I can use in my 60 and 75 gallon tanks. In the winter it is ok because you are heating anyways, but in the summer you are heating the tank and cooling the air which seems like a real waste to me.

I know that gold fish, mountain cloud minnows, etc handle colder water. I am more curious about more interesting fish and plants that can do well in water from as low as 58 degrees F to 75 degrees F. In particular ones that can handle the seasonal change in temperature. The range given is the range of water temperatures from my papyrus water container over a year.

Fish I have considered include:
- Various minnows (boring behavior, to)
- Goldfish (not really my thing, I would consider comets, quite large fish, kind of messy)
- Weather loach (know very little about them)

Plants
- Really don't know what would work, Water lily's?
- Most native plants here require a dormant cycle which doesn't work well with an aquarium, though I am experimenting with local hornwort and mares tail right now.

In general if you have kept any cold water creatures with plants in an unheated tank I would like to hear about your experiences. In particular I like cichlids but other fish types are interesting too.

 

[Back in the fold]

This is something that I am giving serious thought to doing. I currently have 6 tanks running with 450 watts worth of heaters. My fish room is over an unheated crawl space and it gets cold in the winter. It also gets hot in the summer. So hot that I unplug the heaters and leave the window open at night. In the coldest dead of winter my 44 gallon container that I age water in never fell below 64 degrees. Many plants do better in cool to cold water. Anacharis and Hornwort are two. Fish ? Any Central American cichlids like Firemouths or Convicts. Guppies, Zebra Danios, White Clouds, Paradise Fish, Swordtails, Heterandria Formosa mosquito fish, Mollies, most Killifish but especially the South American annuals and North American Fundulus species. Sometimes I look out my window at the electric meter spinning like mad and feel my wallet getter lighter .

 

[outofwater]

I only have 3 tanks, a 10g with a single dwarf gourami there (and 2 snails and plants) and a 29g which I'm still stocking, a few snails and 12 fish in it total at the time. A third tank is planted but set up as plant propagator/quarantine, so no fish. That being said, the spring thaw is finally in full swing and I haven't seen the heaters go on at all for the last 4 days or so. I even had to disconnect the heater in the empty tank (it's a cheap "preset" one) because the water was actually getting over 80 F, it settled at a firm 74 once I took the heater offline. In the colder days that's where the heater was actually keeping it.

The other tanks stay at 74-76 these days, again no heater seems to be coming on anymore, and rhe apartment heat has only come on once or twice at night the last few nights. I don't disconnect the heaters ever, but the thermostats seem to be doing their job. I can only imagine that during the summer I'll have a similar situation where the AC will make the room temp cold wnough that the tank heaters might come on again. It'll be interesting to juggle that and see if I find the right balance.

 

[Colin_T]

NB, I am using my old pc and don't have access to the calculator/ converter on the forum so you lot will have to use it for temperatures in Farenheit.

Unless you keep discus or Uaru, or you live in a really cold climate, you can turn aquarium heaters off in summer, and maybe even in spring and autumn. Most tropical fishes don't live in water that is 24C all year round. Even the water temperature in the Amazon varies during the year. The temperature will drop in the wet season and increase during the dry season.

I set my aquarium heaters on 18C and in winter the tanks would sit on 18 degrees Celsius. In summer as the weather warmed up, the water temperature would go up and sit on 30C+. The fish were fine with these temperature fluctuations because it happened gradually over a period of months.

I had all sorts of tropical fishes in the tanks ranging from tetras, barbs, danios, catfish, loaches, eels, etc. I also had marine fish and they had the same temperatures, except the coral tanks that were set on 22C.

Discus and Uaru need warmer water (26-32C) so if you keep these species, try to keep the water at 26C or above.

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If you have air-conditioning on during summer, you should set the air-conditioner's temperature on 28C. That is a nice temperature for people, animals and fish, and will reduce the power bill, as well as reduce the stress you suffer when going outside into 35C+ temperatures. The tank temperature will then sit on 28C, which is fine for most fish, especially considering it is normally only for a few months over summer.

The human body adapts to cold or hot conditions and it only takes a couple of weeks to do this. If you go without air-conditioning until the weather is hot (above 35C), then the body gets use to the higher temperatures and doesn't suffer as badly when it gets real hot (40C+). The same deal when the weather cools down. A couple of weeks in cool weather and your body gets use to the cooler conditions.

Most aquarium fishes come from Indonesia, which is pretty warm all year round. You don't see local fish farms cooling their ponds or tanks and the water temperature regularly sits on or around 30C+ for most of the year.

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If you want to reduce power consumption when keeping aquariums, try to insulate the base, back and sides of each tank to minimise heat loss. Insulate the top as well using 4, 5 or 6mm thick coverglass.

Try to have all the tanks in the same room and close the room up. Have decent insulation in the walls, floor, roof, windows and doors. Use weather strips around doors and windows to stop air leaks.

Maybe keep the tanks in the main living area so the tank's water temperature helps stabilise and warms the room.

Aquariums are a large mass of water that holds temperature much more effectively than air does. Having the aquariums in a living room will help to stabilise the temperature in that room. And since a lot of people spend a lot of time in that room, the tanks will help keep the temperature more stable for the people.

I know a few people who heated their rooms by using a 200 litre plastic wine barrel/ container with a normal aquarium heater. The container was sealed up and put in the corner of the room, furtherest from an outside wall. Most of the container was insulated. The water temperature got to 30C and the water held that temperature well. The warmth simply radiated out from the container. If there was a power failure, the water retained heat and radiated it out for longer than just heated air would do.

The main way to save power is to have good insulation, and don't set the temperatures too high or too low. The less often the heater or air-conditioner comes on, the less power you use and the more money you save.

 

[I Like Rare Fish]

It is 100% easy, and possible to have a cold water tank. I have 3 tanks/ponds outside. My favorite is the tank. Species of cichlid native to Uruguay, Argentina, and southern Brazil are colder water species, but the best are Gymnogeophagus. Here, water temps can drop low, mid 40s, and become super hot, 80+. However, these fish are very aggressive. I would recommend a small pond or large tank of 125g to keep a group. They are very hard to find. I, and a fellow Gymno keeper, will have some for sale over the summer/fall if your interested. I will ask the pro and see what he says. I know he keeps s wide variety of cichlids outside - Jack Dempseys, and more. Where are you located and what is your average low and average high temperature?

 

[GaryE]

Gymnogeophagus spp - beautiful. cool water but often very aggressive as adults. There are a bunch - some quite stunning, but because they are cool water, they are harder to find.
Aphyosemion killies - my unheated tank favourites - but they are small and minnow-like.
North American darters.
Poecilia latipinna, Heterandria formosa, blue fin killies, sunfish...

 

[I Like Rare Fish]

“Gymnogeophagus Terapurpura, caagazuensis, labiatus

crenicihla Celidochilus and missioneira, australoherosnscitlus and sp local and

geophagus beasilinesis laguna molle are all out year round For me.”
- C. Breeze, a cold water cichlid breeder. This is his stock that he sells.

 

[Uberhoust]

@Colin_T Thanks for the discussion. I do insulate the backs of my tanks. The temperature range I am looking at is the temperature range from my office measured over the year, in water (to account for cooling from evaporation). My cover glass is thin and that can be improved. I would love it if I could keep Angels at a lower temperature, I have been targeting 78 degrees (25.5 degrees), and have recently lowered them to 76 degrees (24.5 C or close enough). I cannot put more tanks upstairs in our living area because the floor isn't engineered for that amount of static load, right now I have the tanks immediately adjacent to a supporting wall where the tank crosses 5 joists. I want to setup another large tank in my downstairs, cold in winter warm in summer, office. The main objective would be to have an interesting species with interesting plants where we don't consider the temperature, if we can live in it then the fish should live in it. I can tolerate pretty cold temp. The tank would be part of my backing when I do my Teams meetings for work.

Did you raise Angels at 18 degrees C? 18 degrees as a min would be much easier to maintain, but it is a pretty big departure from the literature I have read.

@GaryE Of your list I have seriously considered catching sunfish. I see them when snorkeling in the rivers here. I was also considering a signal crayfish, they also live here. I expect the sunfish could be pretty aggressive. My father kept them when I was much younger. I had considered mollys before but my water is both very soft and lacking in carbonates.

@I Like Rare Fish - I live in Canada, currently West Coast of BC, and have for 50 years. The cichlids you mention are very interesting, but right now I am not looking to get an even bigger tank, or at least not now, maybe in the fall. I am originally from Orange Cal. I remember going to many many fish stores in California, when we first moved to Canada there were a couple in Lethbridge one could go to but that was 2 hours away and mostly had guppies and neons. I appreciate the offer but right now I am not inclined to try a bring fish across the boarder. Actually I have never ordered fish, so really don't know what to expect. Also although the cichlids sound interesting I am not setup to deal with their other requirements just yet, they would have to be indoors because my ponds freeze over pretty good each year, the Gold Fish and Minnows don't seem to mind, have kept them in the ponds for over 10 years now. The Geophagus you mention seems like a fish that would fit pretty good but I would need a larger tank for them as well.

I will be keeping a watch for colder water alternatives.

The ambient temp where I would keep these guys would be between 55 to 75 degrees f. May consider a larger tank because my office has a cement floor, but that would have to pass approval from the live in accountant in the family.

 

[Colin_T]

Did you raise Angels at 18 degrees C? 18 degrees as a min would be much easier to maintain, but it is a pretty big departure from the literature I have read.

Most tropical fishes won't breed at 18C (64F), and most tropical fish eggs won't develop at temperatures below 24C (75F). The cooler water was more for holding them over winter and they would breed in spring and summer when the temperature increased.

Most aquarium plants will be fine in water that has a temperature between 16-32C (61-90F). Some Cryptocorynes might not do well if taken from a warm water tank and put straight into colder water but if they are in the tank for a few months before the temperature goes down, they will normally be fine.

A lot of aquarium plants will grow in much colder water too. We had numerous types of Vallis, sword plants, Hygrophila sp, Ludwigia sp, Bacopa, Hydrilla, Java Moss, and a few other plants living outdoors all year round in ponds and tanks. The water temperature dropped to about 3-5C (37-41F) in winter and came up to 32C+ (90F) in summer. The plants were fine but they slow down and don't grow as fast in cooler water.

 

[GaryE]

Standard pet shop fare won't do. They tend to aim for 23 degrees, and sell tropicals only. Sub tropical are special order fish.

Sunfish are aggressive, and can be kept like an Oscar, as a character fish in a large tank. In many places they are classed as game fish and are illegal as pets.

It can be tough because the market is small, and cooler water tends to produce larger fish. Ordering from the States is risky - they seem to check outgoing things, and while I buy killie eggs from all over the world, from the US they more often than not vanish in transit. It's the only place that happens from so it isn't our border doing it. It's legal for us in Canada, but the US has its own ways. You would have to have a mail drop across the border and drive down to pick them up. For beautiful but very aggressive Gymnos though, you'd need big tanks.

There are some rainbowfish from southern Australia that can be hunted down, rarely. M duboulayi can take cooler temps over winter. I've only been looking for it for 5 years....

You could consider going 'hybrid'. There's no reason to sit the tank at 25 all year. You could set your heater for 22-23 in AC season. Or, I doubt you AC down to 58f. I have 50 tanks and 2 heaters in a room I keep at 21 (but I like killies...). I'll probably end up heating 5 tanks in total, but unless I have rainbow fry, they'll be heated low. I expect to keep Aphyosemion killies, a few rapids Cichlids, rainbows, wild type livebearers and Corydoras.

Even when I had warm water tropicals, I unplugged all heaters in May and replugged them in October. I would set the AC at 24.5 to take the edge off our high summer temps, and especially our high humidity, being a cheapskate, and everything worked out.

 

[outofwater]

I trawl the forums just for fun. I'm sure I'll keep some of this knowledge and someday will apply it if I keep increasing my number of tanks and stay at the hobby long enough. This will be the first summer with the tanks in my place, one out of 3 heaters is unplugged, and the other 2 have not come on in a few days, I anticipate that will hold well into next fall. Then again, I'm waiting to turn the AC later in the summer and I'll see how the tanks respond.

 

[Beastije]

I unplugged heaters in my two tanks 3 weeks ago and also stopped heating the whole place, which i had to reverse real quick cause i was cold ) if you have lids, the tanks hold the temperature of the room + a degree. Summer is worse than winter, if you keep the tank in a place where you live most people don't have below 18 anyway in winter. Worse are plants funnily enough, nothing too fancy tolerates low temp. Fish are ok, their metabolism slows down, you can tell when the fish is not doing well based on the behavior. I will post reply during my summer how is the temp holding.

 

[Colin_T]

There are some rainbowfish from southern Australia that can be hunted down, rarely. M duboulayi can take cooler temps over winter. I've only been looking for it for 5 years....

Contact Gary Lange at the American rainbowfish society. He has a Facebook page and sends eggs out to people. If he doesn't have what you want, he should know where you can get them.

Most rainbowfish can tolerate cooler water and will survive cold water after a few generations. I had Melanotaenia praecox living outdoors over winter and the water was 5C.

A number of ANGFA people had Pseudomugil mellis living outdoors in Perth too and they were fine at 5C in winter.

We had rosy barbs, swordtails and platies in outdoor ponds too.

 

[Uberhoust]

Unfortunately I will be keeping my heated tanks for a bit longer, I have some more angel fry now. Thanks for all the ideas.