Outdoor Pond In Hawaii - Survival Experiment

[konakid]

Perhaps you guys can save me (and some fish) some deaths during a trial and error survival experiment. I can't find much info on which "tropical" fish would have a chance surviving in a somewhat unique "subtropical" pond environment. So I thought I would ask here.

I am experienced with aquariums (mostly reef tanks) and with filtration techniques and equipment, water chemistry, etc. I have just constructed a nicely equipped 250 gal. freshwater pond/waterfall in an area of Hawaii that gets a little cooler than what is commonly understood as Hawaii's climate. (2200 feet elevation). So I don't know the ultimate low temperature I will get, but I just checked last night, during what is probably close to as cold as it will get (the end of January), and the water was 68˚F. This will probably be the lowest it will get, and will probably reach this low temperature during a couple of months each year. I would expect the day time temp (its in full sun) to reach 72˚F with daytime air temps around 75˚F. The rest of the year I am guessing the range will stay between 70-75˚F. Of course I will be keeping better track of temps as I gain more experience.

I have not been able to find much info on which of the "standard" aquarium fish have a chance in such a pond. I understand some Platys and Guppies may do OK. And some Swordtails might make it as well. But I was hoping some of the more experienced guys/gals here could prevent some unnecessary deaths, and offer any suggestions of what else might survive other than the typical Koi and Goldfish relatives?

I understand Cichlids are definitely out of the question, but what about Mollys, Tetras, Gouramis, etc. Are they all too tropical?

 

[Mowbz]

Im not sure i agree with attempting the above if your so unsure they will live, but;

I dont think your issue is going to be the cold. We over here in the UK can keep a pond from freezing over in -10'C using heaters. You could do the same over there, and it would only need to raise the temp a small amount.

I think your biggest issue is going to be keeping it cool in the summer. What are you going to do if the temp raises above 28-29'C? You would need to be around 24/7 to dump cola bottles full of ice in the water.....

 

[creeker]

I would look at fish from the barb and danio families. The San Diego Zoo has an unheated open topped tank in one of the bird aviaries. I'm sure it gets cooler than 68 F. They have Rosy Barbs and Giant Danios in there, amongst others.

 

[konakid]

Im not sure i agree with attempting the above if your so unsure they will live, but;

I dont think your issue is going to be the cold. We over here in the UK can keep a pond from freezing over in -10'C using heaters. You could do the same over there, and it would only need to raise the temp a small amount.

I think your biggest issue is going to be keeping it cool in the summer. What are you going to do if the temp raises above 28-29'C? You would need to be around 24/7 to dump cola bottles full of ice in the water.....

Thanks for the quick replies.

Too warm will never be an issue. Where we live (at a slight elevation) the air temp gets over 80˚F only a very few days a year - and then never over 82˚F. So as I mentioned, for the majority of the year I am thinking the range in water temp will be between 70-75˚F. We have one of the "shortest" thermometers in the world here with most days varying by only ten degrees. Average day for half the year is 68˚F low at night, and 76˚F high for the day.

But I just checked the temp in the pond and it is now 67˚. So I think it may be 66˚F by the morning. But again, this is one of the coldest nights of the year. The outside air temp may eventually be below 60˚F tonight, but it will be 72-74˚F tomorrow afternoon. I might also add that we have the highest electric rates in all of the USA. So adding a heater if not really an option.

 

[konakid]

I would look at fish from the barb and danio families. The San Diego Zoo has an unheated open topped tank in one of the bird aviaries. I'm sure it gets cooler than 68 F. They have Rosy Barbs and Giant Danios in there, amongst others.

I lived in San Diego my entire life, and am very familiar with the Zoo. The conditions here in Hawaii are very much warmer in winter than it is there, and at the same time much more mild in that there are no heat waves like the ones that can occur there in summer. So it is about as stable a temp as there is in the world - I am just not sure if water temps between 68-72˚F for a couple of months a year is going to give the "nicer" more colorful tropicals trouble.

 

[Mowbz]

I might also add that we have the highest electric rates in all of the USA. So adding a heater is not really an option.

If you are not adding a heater becuase of electricity rates, exactly how do you plan on filtering this 200 gal of water? If your not, i would jack all this in now, your just goping to kill off fish pointlessly.

Why put fish into something not knowing (or seemingly caring) if they will survive or not? We have some of the highest petrol prices in the world in the UK ( roughly £5.85 a gallon, so around $9), but i wouldnt not use the aircon or open the windows for a dog in the back of the car on a hot summers day. Why is a fish any different?

Unless you are going to provide a sufficient environment, dont bother.

Whether the temp stays stable outside or not, what if it changes? My house stays pretty much the same temp all year round, and all over the house (Back to back terrace, enclosed on three sides) but i still have a heater in case it gets too cold, and a frozen cola bottle in the freezer incase it overheats. Its not porbable, but its possible, and when the time comes, fish will die.

 

[konakid]

I might also add that we have the highest electric rates in all of the USA. So adding a heater is not really an option.

If you are not adding a heater becuase of electricity rates, exactly how do you plan on filtering this 200 gal of water? If your not, i would jack all this in now, your just goping to kill off fish pointlessly.

Why put fish into something not knowing (or seemingly caring) if they will survive or not? We have some of the highest petrol prices in the world in the UK ( roughly £5.85 a gallon, so around $9), but i wouldnt not use the aircon or open the windows for a dog in the back of the car on a hot summers day. Why is a fish any different?

Unless you are going to provide a sufficient environment, dont bother.

Whether the temp stays stable outside or not, what if it changes? My house stays pretty much the same temp all year round, and all over the house (Back to back terrace, enclosed on three sides) but i still have a heater in case it gets too cold, and a frozen cola bottle in the freezer incase it overheats. Its not porbable, but its possible, and when the time comes, fish will die.

I have spent over $300USD for a 20 watt 1400 liter/hr solar pump setup with battery backup and 7ft head for a long waterfall/stream optimized for filtering. It has various controls for flow rates and timed pumping, so I think I can filter it adequately with just that. But just in case I have a backup with UV ready to use if I need to. As I said, I understand water chemistry and equipment set ups - so I am giving these fish a pristine environment.

The only thing lacking is my knowledge of various freshwater tropicals in regards to their part time tolerance of what is slightly below the publicized optimal temperatures. As I also mentioned, the weather here is unique. In the ten years I have lived here the highest temperature has been 82˚F - and only over 80˚F about five times. And the lowest temp has been 58˚F - and only under 60˚F very few times.

Sometimes common and accepted knowledge is restrictive. I grow many rare and what are considered ultra tropical plants here - plants that have been publicized to die if grown where the temps drop below 70˚F. But most do fine and in fact thrive. Temporary or short lived conditions that are marginally outside of what hobbyists believe to be necessary seem to be perfectly acceptable in many instances. In nature, there are always times when the parameters are pushed as well. They are seldom as perfect as in a well maintained aquarium or climate controlled greenhouse. In fact, by pushing the envelope, it sometimes opens the landscape for many more people to enter and enjoy/promote the hobby - and can lead to unanticipated advancements. Something that benefits everyone, including the fish.

But given all the above - the main reason I asked the question here was to avoid simply trying and killing fish that you could maybe tell me will never make it. I thought I made it clear that I was trying to avoid unnecessary agony or death for the fish. I have seen angels, gouramis, and platys living happily in outdoor ponds at sea level here. But as expressed, my climate is about 5 degrees cooler all around, and I thought there may be some here the experience with some tropicals in slightly cooler than optimal, yet still very mild, conditions.

I understand that many here are from the UK and can't comprehend a climate as steady and mild as that experienced here - so it may seem to good to be possible. Our houses at this elevation have no heaters and no air conditioners - some have no insulation or even windows. And I only have one pair of long pants, and one sweater - neither used in years. So I wanted to try something other than the common Koi ponds I see everywhere.

 

[thereverendturtle]

Here's a small list of some more common fish that can handle temps into the 60's...
Most danios
Convict cichlids
Texas cichlids
Several cory cats. You'll have to research exactly which ones.
Paradise fish
White clouds
Hillstream loaches
Guppies
Some plecos
There are some tetras and a few south American cichlids that can take the lower temps too
Black ruby and rosy barbs.

Don't keep gouramis, angels, mollies, anything from Africa, or most south American fish.

I hope this helps.

 

[konakid]

I hope this helps.

Thanks - yes that does help - as I have found very little info on what temps most fish prefer. Instead there just seems to be a standard 72-80˚F range on most sites for everything but the koi, goldfish, etc.

I see there was a request for a sub-tropical forum here some time ago. HERE And while I agree that splitting things up too much is counterproductive, this is the kind of info I am seeking - i.e. what fish are considered "sub-tropical?"

Does anyone know of a site or reference that goes into more detail or groups fish by their preference for water temps. I understand that there are many exceptions such as cichlids and gouramis. Apparently the common knowledge is that cichlids need warmer water, but not all. Same with gouramis - as a rule they prefer warmer, but there are apparently some that can tolerate cooler temps much better than commonly believed.

I am pretty good at researching on the web, but have found concise compiled info on this subject lacking - and am a little surprised it isn't discussed more.

 

[thereverendturtle]

A quick Google search turned this up...
http/theaquariumwiki.com/Categoryub-Tropical_Fish_Species

 

[Baccus]

Not sure about fahrenheit temps but I know my guppies struggled to survive winter in Central Queensland without a heater in their pond. What native fish do you have in your area? Or did you especially want a mix of tropical excotics?

 

[thereverendturtle]

It's roughly 19-23 C. If memory serves, there are no native freshwater fish in Hawaii.

 

[Erik]

This may be a good source for Catfish.

http/www.planetcatfish.com/forum/

Esp. the Cat-elog portion.

I'm on O'ahu, Kailua, so I'm a little warmer than you, but I keep Cories and some Plecos without heaters. Lots of cooler water Cories and Plecos I think would do fine in your conditions.

 

[konakid]

Again, I am appreciating all the feedback and links. Thanks for taking the time.

Not sure about fahrenheit temps but I know my guppies struggled to survive winter in Central Queensland without a heater in their pond. What native fish do you have in your area? Or did you especially want a mix of tropical excotics?

Central Queensland leaves a lot of leeway. Do you recall the coldest your water got, and how much of the year it was under 70˚F (21.1˚C)? And yes, there are virtually no freshwater natives in Hawaii.

Erik knows that because of a heavy Japanese influence here in the Islands, every pond you see is a typical Koi stocked pond. I just wanted to have something different if it was a possibility. Call me a non-conformist.