[Drigo72]

Hello..

I was just wondering what is the ideal water (Tank) temperature? I have a 65 gal FOWLR tank and since summer started my tank temp increased to 80-81*F is this bad? (I live in Palm Springs and our outside temp average 100-111*F during summer)

[leebca]

You're in the dessert -- I'm at the edge of the dessert between San Bernardino and Riverside. We've been having some real hot days this month.

Coral marine fish are pretty tolerant of temperatures in the low 80's. If your fish come from deeper waters or non-tropical waters, they may be used to cooler and darker water. I use a chiller and maintain my system water at 76-77F. The temperature of the aquarium being okay in the low 80's has a lot to do with conditions both inside and outside the aquarium.

INSIDE
The down side to higher water temperatures is that the amount of dissolved gas (e.g., the 'all-important' oxygen) goes down. Healthy fish and perfect water quality in a mature tank will not be a concern as much as the size of the bio-load in the tank. In this case, the 'bio-load' is actually everything using oxygen (bacteria, microbes, pods, worms, snails, shrimp, crabs, (all inverts) as well as the higher forms of life -- fishes).

Some of those above mentioned organisms metabolism steps up with a rise in temperature. This makes it even harder for the fish to get their share of oxygen.

The temperature you have is okay, provided that your aquarium isn't overcrowded, water quality is excellent, and you have a lot of surface movement (to help gases exchange). During real hot spells, it would be a good idea to remove covers or, if you have jumping livestock, replace solid covers with washed plastic screen or plastic light diffuser grating. This encourages evaporation and improved gas exchange. The down side to this is you having to add back distilled or RO/DI water (which can be chilled and dripped in BTW). If, however you have a reef aquarium and some of the inhabitants require strong lighting, screen covering is not a good choice.

OUTSIDE
If the tank is in an open room where fresh air gets to it, you can feel more comfortable about a higher temperature in the low 80's. The water has to have its gas exchange and if the tank is in a closed-off room with stale air of increased carbon dioxide or reduced oxygen, the inside of the tank will suffer. If room air is marginal or stale, then you want to facilitate gas exchange AND bring in fresh air to the aquarium.

This would mean to install fans to circulate air over the tank and around the room which has the same dual advantage -- more evaporation and helping gas exchange as well as circulating fresh air around the tank.

Sorry if this was more information than you wanted.

[greenbean36191]

The ideal temperature for your animals is the temperature they came from. The worldwide average for reefs is about 83. Really there isn't much advantage to keeping the tank lower than that. At 78 degrees, you've increased the O2 saturation by ~0.5 mg/L as compared to what it would be at 86 degrees. Many reef animals are adapted to deal with anoxic periods anyway, since at night respiration on the reef increases dramatically.

Studies also suggest that corals of the same species on the same reef had less reaction to unusually elevated temperatures if they were from locally warmer areas of the reef. They also use less oxygen during elevated temperatures than corals from cooler areas of the reef.

[Ninong]

Originally Posted by Drigo72

I have a 65 gal FOWLR tank and since summer started my tank temp increased to 80-81*F is this bad?

That should be fine for all coral reef fishes. In fact, anything between 76-84 degrees Fahrenheit would work. Metabolism and activity will be speeded up at the higher end of that range. Minimum temps on coral reefs in the tropics rarely get below 77 degrees and average in the low 80's, except in places like the Red Sea where the summer water temps can get into the high 80's.

Fiji water temps.



P.S. -- Don't forget, Fiji is about 18 degrees south of the equator, so their summers and winters are the same as Australia's, not the same as ours. The heavy black line is 2006. Notice that the temperature was above 80 degrees January through June and, in fact, it was above 83 degrees most of that time. In Fiji, the water temperature is above 80 degrees Fahrenheit for eight months of the year: November through June.

Looks like 2006 is shaping up to be warmer than average. I wonder why?

[Drigo72]

Hello

Thanks for the info...It was really very comforting to know that my tank is going to be ok.. i was about to lower the temp of my house to compensate for the rise in my tank temp..(whew saved a lot on my electric bill....)

[fish outa wata]

I too thank you. I assumed that 80-81 would lead to very bad things happening in the tank but now I am not worried. I became nervous the other day when the water reached 81. Thanks for the help.

[Ninong]

If you keep your temperature below 85 degrees Fahrenheit, you will be safe. Even though corals can tolerate brief periods of high water temperature (high 80's F) in the wild, aquariums are a different matter altogether. A temperature of say 86 degrees Fahrenheit is probably the upper limit for most corals in captivity. There are a lot of reasons for this and many of them have to do with the fact that it is impossible for us to mimic many of the natural conditions, especially water flow, in captivity. I don't think it's a good idea to ever let your tank water temperature exceed 84 F.

A safe range for a reef aquarium, IMO, would be 79-83 degrees Fahrenheit. If one has a chiller and is able to maintain tight control of the water temperature, 81-82 F would be ideal. The only reason I don't throw 84 F in here is not because I don't think it's safe, it's because I don't think we should risk the possibility of it accidentally going two or three degrees higher for some reason or other.

[leebca]

Originally Posted by Ninong

. . .aquariums are a different matter altogether.

I'm glad you mentioned this. I wasn't going to.

It is always useful to know facts, such as the oxygen content of marine water at different temperatures, but does this apply to the home aquarium, and more importantly, does it apply to every different aquarium? Not all the time, in my opinion.

The ocean has a vast resource to dilute, prevent, mask, and rectify local water variations. If several oxygen molecules are utilized, more come in to fill the gap from an almost infinite supply -- no noticeable change. But our aquariums are finite boxes. The ratio of water to substrate is nowhere near that of the ocean and reefs. The diversity in the aquarium is so far form the diversity of the ocean, we are like playing with an Erector Set, but the ocean gets to play with mountains.

Last night, Anthony Calfo told our club in his presentation how in reefs, there is usually mono-colonies of corals. Nowhere near the grouping of a wide variety of corals in such a small area (the area of our aquariums). Divers remind us how vast reef areas contain a single coral species, then a ways away, other coral species exist in large areas. We however, like to put different corals next to each other. The sacrifice to this is the energy the coral spends toward competition, vs. what it could spend to grow and thrive.

I appreciate sea physical data and facts, but the meaningfulness of what happens in natural reefs, with all its grand diversity, resources, and vastness to our relatively confined marine aquariums is often a mis-match. Rather than equating what is happening in the ocean to what should be happening in the aquarium, I would rather focus on what is happening in the aquarium and provide the most advantageous conditions for the livestock in that specialized set of circumstances. Take a cue from the natural reefs but check its applicability to the marine aquarium. Just my opinion.

[scooterman]

Originally Posted by leebca

Last night, Anthony Calfo told our club in his presentation how in reefs, there is usually mono-colonies of corals. Nowhere near the grouping of a wide variety of corals in such a small area (the area of our aquariums). Divers remind us how vast reef areas contain a single coral species, then a ways away, other coral species exist in large areas. We however, like to put different corals next to each other. The sacrifice to this is the energy the coral spends toward competition, vs. what it could spend to grow and thrive.

I don't know how many times I've tried to make this point, I've never seen the variety people keep in a tank that close to each other & I have to wonder how can this impact the corals. I hear this all the time, where they try to keep a natural reef, but have fish & corals from all over the world in one small cage, you can't replicate it enough to provide for all of these on one tank.