Re:Skimmer and heat

Pete Giwojna

Dear Potter:

Yeah, it sounds like your big new Reef Octopus protein skimmer is throwing off a lot of waste heat to the detriment of the seahorses, and you’re right to be concerned about the elevated water temperature, Potter. In my experience, Ocean Rider Mustangs and Sunbursts (Hippocampus erectus) are most comfortable with stable water temperatures in the range of 72°F-77°F, with 73°F-75°F being just about perfect for them, and they may begin to experience heat stress and associated health problems when the water temperatures approach 80°F and above for any length of time.

For best results with Mustangs and Sunbursts (Hippocampus erectus), I recommend maintaining stable conditions within the following parameters at all times:

Temperature = optimum 72°F-75°F (22°C-24°C).
Specific Gravity = range 1.022 – 1.026; optimum 1.0245
pH = range 8.0 – 8.4; optimum ~8.2
Ammonia = 0
Nitrite = 0
Nitrate = range 0-20 ppm; optimum 0-10 ppm

As you know, Potter, heat stress is extremely debilitating for seahorses and is probably associated with more disease problems (e.g., tail rot, marine ulcer disease, and Vibrio infections, in general) and causes more mortalities in the home aquarium than any other single factor. There are number of reasons for this.

For one thing, elevated temperatures can have a very detrimental effect on the immune system of fishes. This is because many of the enzymes and proteins involved in their immune response are extremely temperature sensitive (Olin Feuerbacher, pers. com.). Some of these protective enzymes can be denatured and inactivated by an increase of just a few degrees in water temperature (Olin Feuerbacher, pers. com.). So when seahorses are kept at temperatures above their comfort zone, their immune system is compromised and they are unable to fend off diseases they would normally shrug off.

At the same time heat stress is weakening the seahorse’s immune response, the elevated temperatures are increasing the growth rate of microbes and making disease organisms all the more deadly. Research indicates that temperature plays a major role in the regulation of virulence genes (Olin Feuerbacher, pers. com.). As the temperature increases, virulence genes are switched on, so microorganisms that are completely harmless at cooler temperatures suddenly become pathogenic once the water warms up past a certain point. Thus both the population and virulence of the pathogens are dramatically increased at higher temperatures (Olin Feuerbacher, pers. com.).

In addition, the warmer the water temperature, the less dissolved oxygen the aquarium water can hold, so dissolved oxygen levels drop as the water temperature rises. That’s problematic for our prize ponies because their primitive gills make seahorses more vulnerable to low O2/high CO2 levels than most other fishes. Unlike most teleost (bony) fishes, which have their gills arranged in sheaves like the pages of a book, seahorses have rudimentary gill arches with small powder-puff type gill filaments. Seahorses are said to have "tufted" gills because they appear to be hemispherical clumps of tissue on stems. Their unique, lobed gill filaments (lophobranchs) are arranged in grape-like clusters and have fewer lamellae than other teleost fishes. Because of the difference in the structure and efficiency of their gills, seahorses are unsually vulnernable to hypoxia when CO2 levels are high and/or O2 levels are low.

So you did the right thing by leaving the aquarium reflector off today, using fans to blow across the surface of the aquarium and lower the water temperature via evaporative cooling, and floating ice bottles to drop the water temperature down below 80°F again. But those are only temporary fixes and you’ll need to come up with a long-term solution as soon as possible.

[NOTE: I must also caution you to observe all the usual precautions to prevent shocks and electrical accident when you are using an electric fan or any other electrical equipment on your aquarium, Potter.

One such precaution is to install an inexpensive titanium grounding probe in your aquariums. That will protect your seahorses and other wet pets from stray voltage and should also safeguard them electrocution in the event of a catastrophic heater failure or similar accident.

But the best way to protect you and your loved ones from electrical accidents around the fish room is to make sure all the outlets are equipped with Ground Fault Circuit Interrupters. And it’s a good idea to make sure all your electrical equipment is plugged into a surge protector as well to further protect your expensive pumps, filters, heaters, etc. from damage. Some good surge protectors, such as the Shock Busters, come with a GFCI built right into them so you can kill two birds with one stone. So when you set up your cooling fan(s) on the aquarium, be sure they’re plugged into a grounded outlet with a GFCI or a surge protector with GFCI protection.]

In addition to cooling down the aquarium gradually, Potter, you also want to increase the aeration and surface agitation is much as possible in order to improve oxygenation and promote efficient gas exchange at the air/water interface. That will raise those dissolved oxygen levels in quicker than cooling the aquarium will, so consider adding an ordinary airstone or two, at least until the aquarium temperature has gradually drop down to the 73°F-75°F range again.

The first thing I would suggest is to make sure that the new Reef Octopus protein skimmer is installed properly and operating correctly. If everything is working properly, yet the Reef Octopus skimmer is still running so hot, that you may need to think about replacing it with another model.

In general, if it comes down to a choice between maintaining efficient foam fractionation with an oversized protein skimmer and dealing with overheating, or keeping the water temperature in the comfort zone for the seahorses, I would always opt for maintaining the option of water temperature. There are other ways you can manage the water quality in the aquarium aside from a good protein skimmer…

The other alternative would be to retain the large external Reef Octopus protein skimmer to take advantage of the improved water quality it can provide and then investing in a good aquarium chiller so that you can still maintain the optimal water temperature for the seahorses while the Reef Octopus skimmer is still operating, but that might be an expensive solution to pursue, Potter.

The size and type of chiller that will work best for you depends on the size of the aquarium (the total water volume, including the sump), how hot the aquarium runs under normal operation, how many degrees you must reduce the water temperature to maintain the desired temp, and the filtration system the aquarium uses, Potter. Here is a link for a helpful article that explains how to determine what type of chiller is best for your particular system in more detail:

There is a link at the bottom of the article that will show you different types of chillers and what size aquarium they can handle to help you make an informed decision.

I generally prefer the Arctica Titanium aquarium chillers myself, Potter, since they are excellent quality, fairly reliable, and have an excellent reputation. For example, the Arctica Titanium Mini Chiller (1/15 hp) works well for many home hobbyists and is available for around $400, perhaps less if you can find it on sale somewhere. As I mentioned, the Arctica chillers are top quality and very highly thought of, and this particular unit comes preset at the factory to maintain a water temperature of 77°F, and is good for an ambient air temperature range of 50°F-95°. It can be purchased online from Drs. Foster and Smith if it’s not available locally – just copy the following URL, paste it in your web browser, and press the "Enter" key, and it will take you directly to the right webpage to look at this particular chiller and its specifications:

However, when it comes to selecting an aquarium chiller, Potter, that’s something I’m really not comfortable recommending for a home hobbyist from afar. There are just too many factors involved in selecting the right chiller and water pump for the chiller, and then installing them properly is equally important, and every aquarium system and situation is different so that you simply cannot generalize.

For instance, Potter, here are some of the things that you must take into consideration when installing a chiller of any kind on your aquarium.

First of all, you need to calculate the total water volume for your aquarium system and then consider how many degrees Fahrenheit you need to lower the water temperature below the ambient air temperature where the aquarium is located in order to choose an aquarium chiller of the proper size.

Secondly, you must determine the proper flow rate through the aquarium chiller in order to assure that the water passing through it is cooled properly. In order to chill the aquarium water efficiently, the proper flow rate through the chiller must be maintained. If the water is passing through the chiller too quickly it will not be cooled properly in the process; on the other hand, if the water passes through the chiller too slowly, not enough water will be chilled in order to cool the entire tank properly. So you will need to make sure that the pump for the chiller is the right size and has the right output to produce the proper flow rate through the chiller, Potter.

Thirdly, you must not locate the aquarium chiller and pump in the cabinet for your aquarium or place the chiller beneath the tank if you can possibly avoid it. This is because the chiller itself operates as a heat exchanger and therefore releases a lot of warmth as it cools the aquarium water, which means that if you locate the chiller in your aquarium cabinet, all of that heat released from the chiller is going to be confined under the aquarium and heat it up, counteracting the effects of the chiller on the aquarium water. The performance of the aquarium chiller is compromised under such circumstances, which typically makes it much more difficult to achieve the desired reduction in water temperature. (The water pump for the chiller is also a heat source, albeit a smaller one, and can likewise contribute to this problem.) So you do not want to position the chiller and water pump directly beneath the aquarium. And the further you can remove them from the aquarium, the more efficient chiller will be in reducing the water temperature.

If you have no other choice but to keep the aquarium chiller and the pump for it in the aquarium cabinet, then you will need to install vents on either side of the cabinet and include a fan to force the hot air out of the cabinet through one of the vents and pull cool room air into the cabinet through the other vent. This will prevent the heat from building up within the aquarium cabinet and compromising the chiller.

Depending on the type of chiller that proves to be most practical for your purposes, Potter, you may need to plumb it and the water pump that moves the aquarium water through the chiller into the tank using PVC pipe.

When I install an aquarium chiller, I generally prefer the threaded PVC fittings, since they are removable if it ever becomes necessary to modify the plumbing. But the main thing is to make sure all of the fittings in the closed loop for the pump and the chiller to the aquarium and back are absolutely watertight. If there is a need for failure in the tubing that goes into or out of the pump or into or out of the chiller, all of the water from the aquarium is going to be pumped out onto the floor until the water level drops below the level of the perforated PVC pipe.

If PVC pipe is necessary for installing the chiller and/or/water pump, Potter, one other suggestion I would make would be to install union ball valves at the intake and output of the water pump and also at the intake and output of the aquarium chiller. This will add perhaps $30 or so to the cost of the plumbing and installation for the four union ball valves this would require, but it will save you endless frustration and aggravation in the months and years ahead. The union ball valves allow you to easily disconnect the water pump and are chiller for servicing and maintenance, or should they ever need to be replaced, or if you ever want to reconfigure the way they are plumbed. Otherwise, without the union ball valves in place, you will need to cut apart the PVC pipes in order to remove/replace the water pump or chiller or make any modifications and then re-plumb everything afterwards, which is bad enough in itself, but also tends to be extremely messy because the water can be drained from the plumbing and the aquarium while you are attempting to do so.

Those are some of the things to keep in mind when selecting a suitable aquarium chiller and installing it properly, Potter, and that’s a job that must be done on site. If you have no experience in such matters yourself, there are two good options you might want to pursue.

First of all, if there is a good aquarium store in your area with staff that you trust, you can explain your needs to them and allow them to select the proper chiller (and water pump to move the aquarium water to the chiller, if necessary) for you and then to guide you in its installation, or to install it on your behalf.

Secondly, if there isn’t a good aquarium store locally that you are comfortable entrusting with this job, you should hire an aquarium maintenance service to do the job for you. They are usually very competent and will make sure that you get a suitable chiller and pump, and that they are installed properly, and it’s usually not too costly to go with that aquarium servicing company because it’s a one-day job at the most.

Best of luck resolving your water temperature problem, Potter, which is all the more important with the hot summer months fast approaching.

Pete Giwojna, Ocean Rider Tech Support

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