Marine substrate heating 12/18/07
Hi Crew,
<Hello.>
Thanks for all your previous good advice. Every day and with your assistance I am getting a step closer to my dream tank becoming a reality.
<Great!!>
I would like your opinion on the use of under gravel heaters in marine tanks.
(the long rope type that go inside the tank under the substrate, as apposed to the large flat ones that sit under the glass bottom).
I am planning a 900L mixed tank with a 6" DSB and sump. I have a digital Thermostat I was planning on using to power two or more heaters but have am unsure where to place the probe or heaters I have plenty of traditional heaters as well as an under gravel on the shelf from previous years of hoarding in preparation for this big marine setup. Working on the idea that I do want to keep the unsightly traditional heaters out of the main tank.
Would you use an under gravel in the main tank? Would this cause problems with "burning" life close by in this relatively tightly packed (1mm crushed coral sand) or stop it getting cold areas in such a DSB?
if sticking to traditional heaters in the sump would you put the stat probe in the main tank or keep things simple and just put the lot in the sump ?
<I would stick with traditional heaters here. Just not enough water flow through a DSB this thick. You will end up heating the substrate, not the water in it. Put the probe upstream of the heaters in your sump. This will give an accurate reading of your tanks temperature, keep the probe out of your display and make things simple for you.>
Thanks again and regards
Steve H
<Welcome, have fun, Scott V.>

Re: New Tank And How. Heaters  9/23/07
I could not either, but here it is:
http://www.customaquatic.com/customaquatic/itemdetail.asp?itemid=PS-PCRPS-3000
I wonder how we should maintain the proper heat for this size tank. I have a feeling several 100, 200 watt stick heaters will not maintain a
very accurate temp. I am looking for no more than +/- 1F in a 24-48 hour period.
<Any quality heater should give you this. The Jager Temperature Sensor Heaters are said to maintain an accuracy of +/- .5 degrees. Temperature swings of +/- three degrees are not harmful as long the change is very gradual. The lighting system should pose no heat problems with the chiller you have on your quote from Tenecor. James (Salty Dog)>

Won Bros. Heater Failure (A Common Tale?)...What’s A Good Replacement? – 08/20/07
Hello WWM Crew!
<<Hey there Adrian!>>
I currently have a Won Bros. 1000 watt Power Heat II Titanium Heater in my 300 gallon aquarium.
<<Mmm...that’s a big heater...>>
Unfortunately the digital temperature reader went out on me a couple days ago.
<<I had this same problem with a couple of the 300w heaters from this manufacturer...cheap circuit boards I imagine>>
Is there a heater the crew recommends which is more reliable and won't die on me?
<<I make no guarantees, but I did a little research/heard good things about the Finnex electronic titanium heaters so I purchased a couple of these (year or so ago I believe) and they have performed well/are still working well for me at the moment>>
Would it be advisable to use two heaters instead of one?
<<In my opinion, yes...is safer/less chance of damage should one “stick” on...also provides some backup until you get a replacement should one fail. I use a pair of 300w units in my 375g reef and they have proven quite sufficient...but if you want “more power” they build units as large as 500w>>
Your assistance is appreciated.
<<Happy to help>>
Your website is great . . . has taught me many things.
<<Very good to know>>
Thanks,
Adrian
<<Regards, EricR>>

Closed-Loop Musings...And Some Particularly Helpful Ebo-Jager Heater Info From a Reader/User of Our Site – 05/17/07
Hello,
<<Greetings>>
This is my first email to the "Crew".
<<Welcome!>>
I usually just search the site for information.  I am fairly new to the world of saltwater tanks, but I have had a freshwater tank of some sort for over 15 years.  
<<Cool>>
I converted my 125 gallon freshwater to a saltwater tank almost a year and a half ago using the wealth of information from the WWM site.  I had four 3-inch holes (two on each side) drilled on the back of the tank to accommodate 2-inch bulkheads.
<<Excellent>>
The glass company only had 2 or 3 inch bits.  I also plumbed a ¾-inch closed-loop around the perimeter of the tank with 8 outputs.
<<Very nice...and will require a very large/powerful pump to operate efficiently, something in the range of 4800gph after headloss>>
  I ended up capping one output off due to it's proximity to the Remora Pro Skimmer.
<<Mmm, an excellent skimmer...but I would have gone for something a bit larger for this size tank>>
I bought the skimmer before I decided to have the tank drilled.  After reading about the numerous floods and the statement that it wasn't a question of if, but when, I decided it
would be in my best interest to have the tank drilled.
<<Yes indeed...though many such calamities could be averted if hobbyists would employ some redundancy to their overflow systems (i.e. – use “two” hang-on overflow boxes but supply only enough flow to max out “one”)...but still, my preference is to drill for “gravity” drains as you have done>>
I used 2 of the bulkheads for drains for the closed-loop, and one for a surface drain to the sump.  The forth bulkhead is reduced down to 1-inch PVC and then down to ¾-inch PVC in the tank.
<<This last is the sump return line then?>>
The Remora Pro utilizes a Mag Drive 3 pump.  I have a Mag 7 to pump water from the sump to the tank via a one-inch PVC pipe that over hangs the back of the tank.
<<I see...then obviously the fourth bulkhead is “not” for the sump return>>
I also added a Mag 5 to pump water in a loop through a Coral 18 watt 6X UV sterilizer and then back to the sump.   I am only supplying all the details of my setup because I read on the site is better to have a lot of information than not enough.
<<Yes>>
I also plan to reduce the number of pumps I am utilizing.  I bought a Mag 3600 to run the closed-loop.
<<You will likely have to cap a few more nozzles to achieve strong enough flow from the remaining nozzles.  Figure on 550gph-650gph per ¾” nozzle...much less than this and the flow from the nozzles is too weak to be of much use>>
At first,  the pump was unbearable.   I called the company and they sent me a new impeller.
<<Good>>
This did quiet the pump a lot, but the pump was still way too loud for a living area.
<<This is often the case...and the reason I turned to Tunze to meet the flow requirements of my large SPS dominated reef system>>
Also, the pump was mounted externally, but the heat transfer was way too much.
<<This seems to be another common issue with this otherwise reliable/good value for the dollar brand of pump>>
I have since read some of the postings on the site of people that have heat problems and/or noise problems with this same pump.  Most all have the same problem I did.  Way too much heat transfer and way too much noise.
<<Indeed...common as stated>>
The other 3 Mag pumps I have are submersed and are no problem whatsoever.  They work great.
<<Ah yes...and also stated, a reliable/good value pump brand>>
However, I think it would save some people a lot of problems if they avoided the Mag 3600 altogether if they are planning on using it in a living area and/or do not own a chiller.
<<Maybe so...though adding a lot of pumps/pumps of large size of most any brand will cause heating/noise issues in varying degrees (no pun intended), especially in concert with the intense/high power lighting associated with reef systems.  Employing ancillary equipment/methods to deal with heat buildup is something reef hobbyists must consider as a matter of routine in many cases>>
Also, my tank has about 10 feet of head-loss and the Mag 3600 just doesn't pump enough to run the 7 ½-inch outputs on my closed-loop.
<<Ah, ok...you didn’t state the nozzle size previously.  For ½” outlets/nozzles you still need to figure 350pgh per nozzle...or in this case, a minimum of 2500gph after head loss>>
They all have flow, just not enough.
<<Yep>>
2 of the 7 have sufficient flow.
<<All will work fine with a large enough pump>>
Recently, I replaced the Mag 3600 with a Dolphin Amp Master 4000/3000 pump.
<<These are popular pumps for closed-loop systems>>
I was pleasantly surprised.    This pump is super quiet and also, the tank is no longer too hot.
<<Excellent...and apparently worth the extra cost>>
I was amazed that I actually needed my heaters.  Due to some dumb mistakes in my calculations, I ordered the wrong pump though.
<<Really?...still too much head loss eh?>>
I should have ordered the Dolphin 5600/4700 pump.
<<I see>>
Marine Depot stated that if I tried the pump I could not return it.  However, Dolphin Pumps stated that I should go ahead and try the pump and if it wasn't pumping enough they would upgrade it.  Well, they took care of me.  I did have to pay the shipping so I did waste about $20, but Dolphin Pumps is sending me the 5600 pump for the difference in price plus shipping.
<<Very nice...and so good to hear of such service>>
It will also line up exactly with the pipes I have plumbed for the 4000 pump since the pumps are the same size and dimensions.
<<Handy>>
Now that I actually need my heaters, I kept noticing that my Ebo Jager heaters were set almost 10 degrees cooler than the temperature in my tank, but were still coming on.  I have two 250 watt  heaters in my 25 gallon sump.  Well, after checking the temperature in my sump with my digital thermometer I realized that my sump wasn't a different temperature than my tank like I thought.
<<Why would it be?>>
I just assumed that the water was somehow losing heat on its way to the sump.
<<Ah, I see...nope, doesn’t happen that quickly>>
It became obvious to me something wasn't right when the heaters were set lower than the room temperature, but were still coming on.  How could the water be 73 degrees in the sump when  the room was 75 degrees?
<<Could possibly happen under certain conditions (a large system with lights out and fans on, providing evaporative cooling), but in most all cases the pumps/equipment keep system water warmer than ambient room temperature as you surmise>>
I don't own a chiller and the pumps and lights create heat.
<<Indeed>>
Well, after a little searching on the net, I found out that the Ebo Jager heaters needed/could be calibrated.
<<...?! ...really!>>
After measuring the temperature of the sump with a accurate thermometer, I turned on the heaters and then turned them off just till the light went off.  This temperature should have matched the temperature of my digital thermometer.  Of  course, it didn't.  Now I realize this isn't rocket science, but it is very informative and useful for anyone having similar problems.  After turning the knob on the heaters slowly just to where the light goes off, you unplug them.  Then, you pull out on the knob at the end of the heater all the way, turn the dial to the correct temperature, and then push the knob all the way back in.  "Presto"!  I now have two heaters that work correctly.  
<<Wow...great information, thanks for sharing>>
I also found that my sump and tank do have the same temp.
<<Hee-hee!>>
So in the course of about a week, my heat problem was solved, my pump noise problem was solved, and my fish should be a lot happier with the extra flow from the new 5600 pump.
<<Excelsior!>>
Also I read somewhere on the site not to put a shut-off valve before the pump.
<<Can be used for maintenance purposes in conjunction with a union fitting, but should never be used to “starve” the pump.  If a valve is wanted/needed to temper flow it should be plumbed on the output side of the pump>>
This ended up being a pain when it came time to service the pump because I had to block the drains and then drain water out of the pipes.  It is definitely worth whatever head loss there is to have a shut-off valve before and after the pump.  It's a hundred times easier to service or remove the pump.
<<Much agreed>>
Thanks so much for the wealth of information I was able to find on your site.
<<Is our pleasure to serve/share>>
I have learned a lot in the past 18 months or so and I just wanted to pass on some helpful information.  
- Jeff
<<It is much appreciated, thank you for your contributions.  Eric Russell>>

Quartz Emersion heater   4/24/07
I am looking for a Quartz Emersion
<...? Do you mean immersion?>
heater 3 or 4 kw.  Could you give me a cost for one?
<No... we don't sell heaters... Use your search tool/s. BobF>
Karen Burgess

Black sea cucumber burn   2/10/06
Dear Mr. Fenner,
    While reading your article at wwm.com re: sea cucumber, you mention masking the heater to prevent disturbing them.  Could you be a little more specific?
<Yes... mostly the use of "sleeving"... at the simplest, plastic pipe over the unit/s, that is/has been drilled with numerous holes>
Our black sea cucumber recently burned itself on the Visi-therm heater and eviscerated ( we believe ).
<Yikes...>
There were sticky strings in the water and a brown patch on the cuke that later came off.  None fo our other livestock were harmed.  
<Fortunate>
I believe the cuke is regenerating, and I would like to prevent any further harm to it.  I have looked on the web and called my local store regarding some form of heater guard without success.  My husband is handy if given some direction.  Thank you for your time and consideration of this matter.
Respectfully,
Amy Smith
<Mmm, folks/companies have made these over the years, but they were never very popular... log sorts of designs principally... I'd fashion your own if you can't remote these heaters... as to a tied-in (plumbed) sump/refugium. Bob Fenner> Heater Positioning - 2/28/2006
Hi Folks,
<<Hi Johnny.>>
Quickie for you,
Can submersible heaters be positioned vertically? I read that they need to be positioned horizontally to prevent the heater switching off too early due to inconsistent heating. None of the manufacturer's instructions mention this.
<<I position all of my heaters vertically, in a high water flow area.  Shouldn't be a problem.>>
Johnny.
<<Lisa>>

Fwd: heater costs
I would appreciate any information on how much power (kw/h) is used by your heaters.
I have eight aquariums and am trying to get an estimate of heating costs. 
Thank you 
<We don't sell heaters... most uses call for 2-3 watts per gallon... kilowatts per hour depend in turn on insulation values, differences in external/internal values... You can hook up devices which will monitor, measure your electrical consumption... or guesstimate how long each are on... multiply the wattage times the time... to get kilowatt hours used... multiply this in turn by cost per kilowatt (see your electrical bill)... to find cost. Bob Fenner>

If you can't take the heat, stay out of the tank.. 2/17/03
Thanks Phil!<No problem man!>
That heater thing... I have no problem adding more heaters, but where?
I figure the 350 in the sump of the wet/dry....can I put more than one in there and have them accurately assess the temps or should I just get a controller for heat/cool and put the probe in another part of the system and let the two heaters run in the same sump?
<If you go the route of more than one heater putting them on one controller would be best and they can be place near near each other!  A dual controller is rather costly at Pet Warehouse I believe it's nearly $200.  But of course it's up to you.  If you want to do two heaters w/o a controller they need to be IMO placed at different ends of the tank.  If they are together they may overheat one area and under-heat the other.  Hope this helps!  Phil>

Sump melted by heater?
>Hello to all at WWM:
>>Good morning, Marina here.
>This might sound like a silly question but here goes. I currently have two 200w Visi-therm heaters in my sump. I have always been concerned if the suction cups did not hold and the heater actually was laying directly on the acrylic can it in fact melt the sump?
Always wondered......never asked until now.  Thanks a million,
Gene
>>If the sump is acrylic, and the heater were to become stuck in the 'on' position, yes, it could happen.  Is it *likely* to happen?  Not very likely at all.  But, if really concerned, then you could simply slip them into a sleeve of PVC, with many holes/notches cut into it, they won't usually be sufficiently hot to melt PVC.  I would like to suggest spacing the heaters, though, to help reduce temperature differentials.  I like having one hidden in the tank, and one remotely located (the sump).  

Lifeguard heater modules
Is it possible to use two of the heater modules together with one canister filter, or would this be to much pressure for the pumps to deal with?
If it is to much to use two on one filter, should I shoot for using two filters and two modules? I'd rather not, but gotta do what's best.
<Good question. I would use a larger wattage heater first here (likely there are up to 300 watt units that will fit), and if you need to use two, set them up in parallel (not series) to save on induced resistance. And after located after the canister filter of course. Bob Fenner>

Re: lifeguard heater modules
What do you mean by setting up two heaters in parallel?
James
<Running water through a "tee" to each module separately, rather than (in series) one after the other... Bob Fenner>

- Ich & Kerosene Heaters -
Hi.
Two questions, if you have the time.
I have recently set up a new salt water tank, going great, except for some ich.  I got a cleaner shrimp and he seems to be keeping it under control. I want to try this before I catch all the fish and return them to the QT, and let the system go fallow. Is this ok? <In the interim, sure... but there's really no guarantee that the cleaner shrimp will actually keep things under control. In the long run you very well may end up fallowing the tank.> I really do not want to resort to chemicals if I don't have to. <I don't blame you, but this may be what's necessary if the fish go back to quarantine.> I have not done any fresh water dips as of yet.  I am not sure how to raise the pH to 8.3. <Baking soda.> My fresh water pH adjuster can only get it to 8.0 and then not for long.  Beside I have no idea what the chemicals that raise the PH will do to the fish.  Only two fish have a couple of spots on them and they keep going over to the shrimp. He is not eating all the white spots but spends a lot of time on the gills. Neat to watch. They are not breathing rapidly or acting strange such as darting, scratching, or hiding, they eat well.  I am not sure what made the ich appear. <Hmm... under the worst-case-scenario, the parasites have dropped off to breed in your sand bed. They'll be back.> I have no temp fluctuations as I use two heaters it is always 78F day or night even if the basement gets cool. Ph 8.3, alk high (I know get a better test for that), ammonia 0, nitrite 0, nitrate 0, calcium?, LFS is having trouble getting this test kit for some reason.   I did quarantine each fish for 4 weeks, and let the tank cycle for 6 weeks with 45 lbs of live rock, before I added my first inverts and corals.  Anyway I read your ich pages.  I am a little confused, some say let the system go fallow, and others recommend what I am doing. <Personally, I think cleaner shrimp can get overwhelmed, not be able to get everything and the problem blows out into epidemic proportions. Do keep an eye on things and keep that quarantine tank ready to go.> Lots of opinions about it though. <It will always be thus.>
The big question though is this.  I heat my basement (this were I keep the tank) with a kerosene heater, as it is much cheaper than running my electric baseboard heaters. Is there a danger in this, and if there is, what is it, and what should I look out for? <Egads, there is most certainly a danger of primarily carbon monoxide which can kill you. It has no odor and can build up in an enclosed space like a basement. If I'm not mistaken, kerosene heaters aren't meant to be used in enclosed spaces. There are other toxic byproducts of combustion that should be worried about, but those will only make you sick - CO will kill you. So yeah... there are issues with using this in your basement not just for your fish but for you as well.> Is there a test kit I should be using? <There are electronic CO detectors, I would plug in at least one of these.> I cannot afford to upgrade my whole house heat as that will run into the thousands of dollars, last quote I got was 8 grand and some change. <Then get some big heaters for your tank.>
Thank you very much in advance
Craig B.
P.S.  Is there a web site where I can download a log book designed for salt water tanks? To use with Word. <I've not seen any products like this, but I'll refer you to Aquarium Journals who makes a log book for keeping track of such stuff. http://www.aquariumjournals.com
Cheers, J -- >

- Heat Solution in Event of Power Loss -
Just a quick suggestion. <Sure.>
During loss of power (electric), aquarist loose the heater function... my suggestion is to use hot water bottles...(Rubbermaid one's)... stick em in the tank... this should work right..? <At least for a little while, but if the hot water is generated by electricity then there would be trouble. It's a good suggestion, but I also suggest wrapping the tank in blankets to help slow the heat loss in the first place.>
Jess
<Cheers, J -- >

Saltwater Pond in SoCal?
Dear WWM Crew, 
<Sean> 
First, and foremost, thank you for staffing such an incredibly informative site! Between WWM and ReefCentral I've been able to answer countless questions over the past three years that would still be mysteries without you... On to the topic -- I'm evaluating the feasibility of adding a saltwater pond to the 1000+ Gal reef system I am in the process of installing.  The indoor portion of this system will consist of a 575 Gal display tank in my office, and approx 500 Gal of refugium/grow out/sump volume. The pond I am considering is roughly 12' x 8' x 4' deep, or ~3000 Gal. The two would be plumbed together via the 200 Gal sump. 
<Okay> 
The display will have roughly 6500 GPH of flow, and I was planning on the same amount of flow to the pond/lagoon via a separate pump. My idea is to keep SPS coral in the display, and run the lagoon as a large FOWLR section of the system. 
<So far...> 
My area of greatest concern is around temperature.  After researching this for the past two months it seems that a gas fired heater and heat exchanger would be the most economical way to keep the system warm in the winter months. Unfortunately, I am having trouble sizing this. These systems are rated in BTU/hr, but I can't gauge my requirement without local (to SoCal) 
pond anecdotes on temp in Koi/Shark setups... specifically, I'm curious to know what fluctuations folks experience in their ponds that are NOT heated/cooled. I've found a good deal of information on your site, but no specifics as to average seasonal 
pond temps in this region. 
<And so a bit more info. on historical temps in the area would help... but a rough guess... 100-200 BTUs... There may well be a better long-term thermal regulation mechanism in the way of plumbing a recirculation line through a line that would through an exchanger and your gas-fired water heater... with a thermostatic mechanism to set the temperature. Bob Fenner> 
Any help you can provide in that area would be GREATLY appreciated. 
Regards, Sean

Heater Question
hi, I was wondering what sort of watts for my heater should I be getting for my 4 ft tank?
<Hi, Ryan with you.  I'd recommend at least 3-4 watts per gallon of water in your aquarium, although with more flow, I'd recommend 5 watts per gallon.  If you use a sump, don't forget to factor that in to the total water volume!  Good luck, Ryan>
thanks

Heating an aquarium? - 11/17/04
So, my tank is 55 gallons, the sump is in three compartments, 1st is the skimmer part (kind of the actual sump) about 10 gallons, the next is the refugium about 10 gallons, next is the exit out to the main tank with a pump about 3 gallons.  Anyway, I have put the heater in the refugium part (ok?) now, <Should be fine. Curious as to why you would think it shouldn't be placed there?> should this heater be 200 watts or only 50 watts cause its in only a 10 gallon area? <Is the heater responsible for heating the total of all gallons in the aquarium? From what I can tell you have a 55 gallon tank with another 23 or so underneath, correct? So, now you need to ask yourself is this heater to heat the entire volume of the tank? If the answer is yes, then you need about 5 watts (my personal preference) per gallon. So in your case, you would need to heat 75 gallons (I rounded the numbers a bit), so 75 gallons times 5 watts per gallon equals 375 watts of heater to efficiently heat 75 gallons of water. Understand where I came up with the numbers here?>  And would 200watts be too much for a 10 gallon area. <If a heater works properly it would be fine. However, if the thermostat were to malfunction it would easily overheat the tank in a very short amount of time.>  Would the heater heat that area too hot for a refugium and its Chaetomorpha and worms and such? <See above answers.>
I have a euro reef skimmer and it recommends that is should be 6-8" of water, what if I have say 9-10" would it not work well. <Not sure what you are asking> Also, how high should the intake pipe be, to the top of the container, or up into the neck? I should probably ask euro reef, huh? <I do think that would be a better place to ask as I am slightly unfamiliar with their product. Plus, why wouldn't you want tech help from the manufacturer first? In any event, I hope I was able to help shed some light on your issue and help you gain some understanding regarding heating an aquarium. Thanks for participating in the greatest underwater community....WetWebMedia. ~Paul>
anyway
Thanks
Mark

Thermal question
I am moving to topsail, NC....however, there is no place for my tank in this person's house....he does, however, have a downstairs that is not insulated.....would it be possible, if I spent the right kind of money (but not too much), to keep it down there for about two months....I am assuming it would not be that hard to heat?  I could buy 3 or 4 heaters for the tank....a digital thermometer....would it even be possible?  any advice or suggestions would be great.....
<Actually, most places in NC aren't "that" cold. Should be able to get by with five or so watts per gallon... if it were mine, I'd also stock a "thermal blanket" (such as those sold for water heaters) to aid in insulation. Bob Fenner>

Re: Thermal question
I was thinking of putting 3 nice heaters in the tank....putting one on 78, one on 76, and one on 74... and purchasing a digital thermometer.... any particular brands you suggest for heaters?
<Ebo-Jager and the new Aquarium Systems products. Bob Fenner>

- Heater Won't -
My Jalli 500 watt heater keeps quitting on me. <That's not good.> I have a 90 gal tank with a 20 gal sump, the heater is in the sump, has never come out of the water while plugged in, is not covered by anything, the control head is properly mounted and connected, temp probe is in the middle of the tank.  I just got the entire heater replaced 4 weeks ago, under warranty, because of the same thing. <Nice to see they're batting 1000.> Is this a cheap heater? <I'm not a huge fan of Jalli, but I know someone who is and swears they [Jalli] try very hard to get past problems like this. If it were me, and I'd had two heaters broken, I'd ask them to buy me a new heater. There seems to be a flood of heaters with electronic controls coming from Asia... I think each one needs to be well tested before tried on your main tank as you might be in for a surprise.> Would I be better off with 2 -250 or 350 watt units? <In the cold parts of the country, I would suggest having two 350's with one set a little lower as a back-up should the main one fail. With larger heaters, they tend to be 'on' less often, can heat a given volume of water quicker and I think [in my own weak non-scientific study] they will last longer. Any under or exactly-sized heater that is 'on' all the time will break eventually, regardless of brand - is just my observation, but have seen it happen often enough.>  I do have a 250 watt backup working now, it struggles to keep 78 degrees. <Using two 250's would guarantee the failure of one, and then the other.>
Chilling here in Pa, thanks... Mike
<I believe it. Cheers, J -- >

Heaters
I have a question about heating the tank. <sure> My main tank is a 50 gallon and I have a 29-tall underneath serving as a sump.  In the main tank I have a 150 watt Ebo Jager and a 100 watt Ebo Jager heater.  These heaters stay on most all the time.  Sometimes one or the other will go off briefly.  My question is, does it hurt anything for them to run almost continuously?  I have a large ritteri, an ocellaris, and a bicolor blenny.  I keep the tank around 81 F.  The temp is very stable.  The room is usually in the mid-70's.  Is it okay for the heaters to run so much? <Shouldn't be a problem, seeing as that's what they're made to do.  Ebo-Jager heaters are very durable, so I wouldn't worry about it.  Also, for future reference please capitalize "I" as well as the first letter in every sentence.  M. Maddox>

Re: Temperature Fluctuations
Hi Bob,
<Walt>
Thanks again for the response. I took your advice and returned my heater. It was only a month old and I still had the receipt so they refunded my money no problem.
<Great>
I tried in vain to locate a Eheim Ebo Jager heater but to no avail.
<Strange... should be available from online etailers... Ken Wong/Marine Depot, Bayside distributes Eheim in the U.S.... they must list them. Wow, actually, they don't! In fact, I don't see them listed by anyone... must be a demand/request of the manufacturer... now owned by Eheim... which ARE sold by discounters...>
I did a bunch of "consumer review" searches on-line and found consistent positive reviews for the Aquarium Systems (Marineland) Visi-Therm heaters.
<Ah, yes, also fine products>
My local pet store stocks them so I went and bought a 250 watt unit. It held the temperature to within one degree overnight and that is saying something as it was very cold up here in upstate NY. Have you had any experience with the Visi-Therm models? Thanks again.
Sincerely, Walt
<Yes, a great deal... have even been to Italy where they're made... Bob Fenner>