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Why have a heater ?

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With all the updates on getting heaters, curious on a no-heater set up.

i keep our home at < 75 in summer and > 68 in Winter. My aquarium water temp seems to correlate well with the room temp. A temp range of 68 - 75 seems ok for CPDs and potentially for neocardinas.

Do people in climates similar to the us midwest, have experience with not having a heater ? what is the downside ?
 
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Neocaridina and caridina are good at most common "room temps". CPD's are great at room temps too.

Most tropical freshwater fish are probably too cold at room temps. I keep my house between 70-72F year round in most cases, and that's too cold for these fish (many of which come from waters that are 78F-85F year round).

Also, if your winter temps get really chilly, it can hurt your inhabitants and also affect plant growth. A lot of plant metabolism is dependent on temperature; too cold, and they simply will struggle to grow.

I keep all my heated tanks between 73-75F, which allows me to keep 90% of freshwater fish and shrimp just fine, and is a good temp for plants too.
 
Do people in climates similar to the us midwest, have experience with not having a filter ? what is the downside ?
Assume "filter" was meant to be "heater" there.

For me in KC, I think my tanks on the main floor would be able to manage most of the time without the heaters, especially as I age and tend to feel chilly more and more often. Don't even get me started about how cold I feel when I go into the office. The basement runs cooler so I think heaters are more important there, but even on the main floor, I did keep an eye on the inkbird app to see how often and for how long the heater ran on my 49g tank. It cycled at a fairly consistent rate to keep the tank at a steady temp and I think that's where the value of the heater really lies, keeping that tank parameter very consistent. We've read a couple posts here where things went off the rails in a tank and it ended up being a temp related issue.
 
My Biorb (Ember tetras, Neon tetras, a few Endlers and shrimp) and Hillstream tank are unheated. My heated tanks are between 73-75, but I did keep one at 78 when I had a Betta and Green Neons. I went without a heater in the previous Dutch tank for awhile, but the basement drops to 68-69 during portions of the day in the summer. The air conditioning cools the house unevenly, so it’ll be 76 on the top floor, 74 on the main floor, and much colder in the basement. I put a heater in just to keep the temp steadier and where it should be during those times.
 
Thanks all

I recently saw a YouTube interview of sudipta Shaw on the weekend aquarist and his talk on AGA and he noted a correlation between lower temp and better plant growth. The talk was a little vague on the actual temp.

Curious if anyone has more input on the absolute lower temp range where the typical plant species that we grow (eg, rotalas, AR, Blyxa etc.) stop doing well.

On a different note, assuming in nature there is a good temp fluctuation, do any of you know of people doing experiments to see what plant growth does with stable vs fluctuating temps? To Jays point I do remember @BenB post on temp being a cause for an algae bloom, but if I remember correctly it was higher than lower temp?
 
As mentioned above, main living space smaller tanks are fine without a heater. I don't heat my shrimp tank for example, that sits between my kitchen and family room. Also not heating my quarantine tank at the moment, as it still has the white clouds in it, and they don't mind cooler water. My 150 U is in the basement. I actually dark started without a heater, which is probably why it took a little longer, as it struggles to get above 66-67 degrees without a heater. The space is conditioned, but not overly warm. The heater is really just to maintain temperature stability, and set to 23 C/73 F. A slightly better temp for beneficial bacteria, and tank inhabitants, than a chilly 67.
 
The heater is for the livestock. CPDs are cold water fish and do pretty well room temperature or even below room temperature. But quite a few fish would absolutely kick the bucket if in the 60s for more then a day or so.

I keep newts which are cold water animals. I put a fan on my tank to drop the temperature below room ambient and in the winter its not uncommon for my tanks to be in the lower 60s or even upper 50s for months at a time. I have absolutely no trouble growing plants at this temperature and frankly have not run into any species that don't grow at these temperatures. It os possible some types of algae do not grow well in colder waters or I've just gotten good at balance, one or the other. :P Because I don't tend to see much algae in my newt tanks.
 
The heater is for the livestock. CPDs are cold water fish and do pretty well room temperature or even below room temperature. But quite a few fish would absolutely kick the bucket if in the 60s for more then a day or so.

I keep newts which are cold water animals. I put a fan on my tank to drop the temperature below room ambient and in the winter its not uncommon for my tanks to be in the lower 60s or even upper 50s for months at a time. I have absolutely no trouble growing plants at this temperature and frankly have not run into any species that don't grow at these temperatures. It os possible some types of algae do not grow well in colder waters or I've just gotten good at balance, one or the other. :P Because I don't tend to see much algae in my newt tanks.
Yes, it seems that if the livestock can tolerate the temp, colder temps seems to have advantages for both plant growth and less algae.
 
With all the updates on getting heaters, curious on a no-heater set up.

i keep our home at < 75 in summer and > 68 in Winter. My aquarium water temp seems to correlate well with the room temp. A temp range of 68 - 75 seems ok for CPDs and potentially for neocardinas.

Do people in climates similar to the us midwest, have experience with not having a heater ? what is the downside ?
So I grew up in Bangladesh; a lot of the nano fish are from that region of South Asia, and a lot of the plants in the hobby are also from that region. I personally don't think that it's correct to say that nano fish coming from South Asia can't live in cold waters; a lot of these fish, such as the glass perchlet, Badis sp., gouramis, rice fish, barbs, and even pea puffers, come from regions where water temperatures can really plummet in the winters; I'm saying sub 15°C. It's the same with plants (Blyxa, eriocaulons, rotalas, eleocharis sp), which also live quite well in low temperature ranges of around 12-15°C during the winter. Are these optimal temperatures for plant growth and fish breeding? Not really. But what I wanted to point out was that you could technically keep your tank's heater free depending on the species of fish you intend to keep and the level of growth you want from your plants. Most homes in the winter are temperature controlled between 20 and 22 °C. I don't think a heater really is needed in that case. This is specifically the case for South Asian species btw, I would assume that species from the amazon basin or Southeast Asia would require higher temperatures of around 22 °C as these places typically don't get too cold. But even in those cases you should be ok given how adaptable most fish in the hobby are and how most homes are at a comfortable temp of around 22 °C.
 
it seems that if the livestock can tolerate the temp, colder temps seems to have advantages for both plant growth and less algae.

@Dennis Wong mentions that the slower growth at lower temperatures can also lead to more compact growth forms for stem plants , to a point, below which the plants thrive less or stunt

 
South Central Texas, haven't run a heater in probably 7+ years. I've had too many problems that I'm convinced there is no such thing as a good heater. I've had them fail both directions off or on, and when it failed ON it literally killed everything in the tank but my nerite snail who was able to climb out of the water, but I'm talking hot tub temperatures, I could literally feel the heat radiating off the tank when I approached it. I realize they have thermostats and ink birds (which I have) but i simply don't bother with it. I also am not really a big fan of having any kind of power cord going directly into water. I don't care if they were built for it, things age, deteriorate and fail. I know there are way you can ground your aquarium, but personally I feel all the risks outweigh the benefits..... So I can't keep some species, I can accept that.
 
Find attached an interesting read as i was getting to the rabbit hole of temp and algae as well.

TLDR - the articles speaks about filamentous green algal growth that includes spirogyra in shallow fresh water system. They noted that the optimal temp for the bloom would be around 68 and less algal bloom at 75.

Interesting and counter-intuitve to what i would have thought. Lot of confounders to its applicability to us (or atleast to my tank with its filamentous algae) but would be interested in more info people have on such research.

We have something called as a journal club in my field of work where we discuss an interesting article weekly, might be a good idea for scapecrunch; where we post a journal article relevant to us and discuss it.
 

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It mostly depends on the exact room temperature we're talking about.

I don't know too much about plants, as I only have low tech species so to speak. But in an average home where temperatures don't drop too much during the colder months, I think many so-called tropical fish will still be fine in unheated tanks. 🙂 For most species a water temp of 20-21 C (69 F) is acceptable, especially if it's only that low seasonally.

My home is in western europe, where winters are mild compared to those of the midwest. It's well isolated so even in winter, it doesn't get too cold. When I don't heat the home, for example when I'm away for a number of days, I just let tank temperatures drop naturally. They sometimes fall to about 18 C (64 F) or slightly below, with the average winter temperature being around 20 C (68 F) I think. None of my fish, among which are subtropical as well as tropical species, really seem to care. Yes, some do slow down and eat less in the colder months. But they're all still healthy and generally they live long lives.

So in my experience, while there always will be exceptions, a lot is possible as long as you keep your home in a temperature range that humans are comfortable in. 🙂 I think the youtube guy from Aquarium Coop said the same thing; in many homes, heaters are optional.
 
A lot of aquarium equipment generates heat like light and filter. Add a lid and it gets pretty warm.

If you have an internal filter with lights and you have a good lid on your tank without giant airholes, your tank temp will usually be 3-5 degrees warmer than ur room depending on how bright ur lights are.
 

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