watts per gallon SW and tank heaters?

[greenmaji]

When MH and large water pumps come into play Im sure heater wpg rules change.. so.. how do you guys calculate the needed water heater size?

 

[Hara]

All I can say is that I have heaters in the sump and they NEVER come on. Between the lights and the pumps, I get about a 3 degree temperature swing at the most. (your mileage may vary).

 

[greenmaji]

could you give me some idea about the heat generating equipment that is connected to that tank? TIA

 

[fishfreek]

IMO there are way to many variables to try to calculate out the effect the lights and pumps do with out trying it in real life. The ambient room temperature the amount of water evaporation you have can be real big factors in if you need a heater just for supplmental heating when the lights are off.

When your using MH and the lights are on indeed most of us dont need much support from the heater. Although if you have good evaporation that alone can significantly counteract the heating properties of the MH bulbs. In addition you need to factor in the dark times of the tank when the lights are not heating the water. At that point in the middle of the night the heaters might cycle on/off a few times to maintan temperature. If your ambient temperatures in the room are higher than less heater will be needed but if you keep your abmient room temp low like in the high 60's then a larger amount of heater will be needed to maintan a tank temp of 80F.

 

[Genix]

All I can say is that I have heaters in the sump and they NEVER come on. Between the lights and the pumps, I get about a 3 degree temperature swing at the most. (your mileage may vary).

perhaps you should raise your heater thermostat by 3 degrees to avoid temp swings?

i have an aquaclear 100 watt heater in my 15 gallon nano. a bit overpowered, but my temp is ROCK-SOLID. we're talking like +/- .25 degrees F. lights on, lights off, day, night, no matter. always a solid 80 degrees.

 

[greenmaji]

I keep the room tem in the mid 70's..
And I am planning on using lower wattage MH.. 175's but Ill likely have some supplemental lighting.. VHO would be the hottest of my options.. T-5 HO the coolest but that might be oppinon.. I might OD some T-8's for 03.. Im likely going with 10,000K on the MH.. it will be a LPS tank.. they done make 6500K in 175 MH.. or I would consider those..
as far as pumps go.. the pump for the sump will be small.. the closed loop pump will be the big one.. once I deside on how much flow total to go with.. that should be a less heat situaltion..

So it might be best to set it up and see how much the temp swings before livestock is put in to gauge how big the heater(s) need to be? TIA

 

[No_Floaters]

I have a 92 gallon bowfront with a Mag 9.5 for the return and a Mag 3 for the skimmer on the sump. These keep the water temp at 80-81 degrees constantly with room temp between 74 and 76 degrees. I run 4-VHOs and 2-PCs for the lighting, but they don't make hardly any difference.

But as a guide for heater wattage: take the tank gallons and muliply by 3 (watts per gallon). Take that number and divide by 2. That will give you the wattage for 2 heaters.

2 heaters decreases the chances of cooking your tank if it fails while it's "ON".
Here's a link that explains what can happen.

http://www.dfwmas.org/Forums/viewtopic.php?t=13198

I forgot to mention it above, but my temp range was so small, I only have 1-175W heater in the sump.

 

[greenmaji]

No_Floaters.. thanks for the info on what can happen when heaters go bad.. Ive been in the hobby close to 17 years now.. Ive had a few close calls myself..
Im just not used to all this heat generating equipment in and over my tank.. I lived close to Chicago and everyone up there used 5wpg for there FW tanks (lack of heat generating equiment in the system) but it gets VERY cold up there.. if your heat goes out... 20 below zero isnt unheard of in your house when you wake up.. 8O I dont think any heater would help in that case.. and Im not afraid of the heat going out here (Its a new place with new equipment)
so.. the coldest it gets before I get to the thermostat in the temp fluctuating seasons such as now.. is in the mid to high 60's.. Im pretty sure I could get a thermostat that would swich between heat and cool if I did my reaserch..

 

[greenmaji]

man was I babbling.. :?

So it might be best to set it up and see how much the temp swings before livestock is put in to gauge how big the heater(s) need to be?

Is this what most people do or do you guys and gals just take a wild guess around 3wpg?

 

[fishfreek]

Its not like having to big of a heater is going to be a bad thing. For my 75 gal tank I have two 200W heaters.

 

[pelochas]

forget calculations
i just went and bought a neptune aquacontroller JR with temp and ph probe. also came with 8 programmable outlets. set the temp and plug your heater (set the heater for about 82) and let the controller turn the heater on or off when needed. no calculations, just a lot of money though but you get so much more options though, wave making, on off timers, etc...

 

[HoopsGuru]

Hamilton makes a 6000k 175w bulb, just wanted to throw that out there. I would still go with 10k but that is personal preferance.

 

[Brenden]

I have 4 200w heaters in my sump that have never come on. Definetly get the temp swing down to a minimum before adding livestock. My tank now drops to 77.4 at night and maxes at 78.5 during "lights on". Summer averaged one degree warmer.

 

[greenmaji]

I have 4 200w heaters in my sump that have never come on. Definetly get the temp swing down to a minimum before adding livestock. My tank now drops to 77.4 at night and maxes at 78.5 during "lights on". Summer averaged one degree warmer.

I might be wrong but Im not so sure 800 total watts of heaters would do much for your system.. ROFL

Hamilton makes a 6000k 175w bulb, just wanted to throw that out there. I would still go with 10k but that is personal preferance.

thanks for the info. Hoops.. I dont think I would try anything under 6500K since I have the option to go a little higher.. the 10K sounds cool.. I probibly dont need any more light then 2 175's and could just go with 14K's and leave the suplemental light out.. Im still debating.. thanks..
btw. one of my MH ballasts came in the mail today its a magnetic and man was that thing bigger then I was expecting..

Its not like having to big of a heater is going to be a bad thing. For my 75 gal tank I have two 200W heaters.

Agreed, not a bad phlosopy to have.. always better then not having enough.. your running VHO on the 75 though.. probibly less heat.. but I doubt your heaters are running alot anyway.. Thanks again..