Substrate heater

[alacroix]

I am putting together a 90 gallon (48x18x24)  planted tank.  I want to install a substrate heater. I understand the theory behind the use of a sustrate heater.  However, I am nowhere close to making a decision on what system i.e. 24 volts or 115 volt, nor the wattage required.  I read recommendations from 40 watt to 250 watt.  I've investigated Root Therm by Redsea, Hydor Hydrokable and Dupla...

Any recommendation from an experienced user?

[Aquaviewer]

I wouldn't say I'm overly experienced but this is what I've found.  There are numerous recommendations on different forums and from manufacturers on how to size the system.  Dupla is the premium line and very $$ and hard to get (and the old systems are being discontinued) and the others fall inline.  Price is driven by the length of cable (wattage) and whether there is a thermostat.  Brand loyalty seems to be one of the predominant drivers of choice.

Overall this topic has been debated many times over on numerous forums and the opinions are as wide ranging as the number of contributers, but generally they fall into two schools of thought.  1) Substrate heating (SH) is the only way to go or  2) SH its all bunk so use the money you would have spent on SH on more plants and fish.  The former school of thought, primarily promoted by Dupla and supporters, suggest that SH contributes to the long term stability of the tank and reduces algae growth.  (SH appeared to be popular with those who use laterite as opposed to some of the newer substrate mixes (Florite, Eco complete, etc...) ).  The later group feels that there is no apparent difference and all things considered proper care is all you need.

I did a bit of research into this and installed it in one of my tanks to check it out and compare it to the other planted tanks - I did not notice any startling differences.  After a period I unplugged it to see if I could notice a change in growth. Over a year later and growth is great and the tank is stable so i haven't bothered to plug it back in.  However, I now have plant roots tangled all around the cables that get pulled up every time a go to move a plant! 

After reviewing the contest entries in the AGA planted tank contest(http://showcase.aquatic-gardeners.org/2006.cgi) I noticed that many of the entries did not use substrate heating.  Hmmm, interesting....

This is just my opinion and more experienced folks likely have more robust observations and opinions

[babblefish1960]

I would agree with aquaviewer's observations. It is something that seems to me to be unnatural, and though everyone loves radiant heated flooring, I suspect that plants do not. In their home environments, the earth they cling to is always cooler than the top strata of the water. And like undergravel filters and plants, something that can become a problem down the road. Moreover, an equipment failure would be difficult to diagnose as well as requiring a full tear down of an established system to repair or replace. Just my opinion as well.

[alacroix]

Thank you for providing your observations and opinions.

[busdriver]

I have a substrate heater in my 75 gal and everything is growing well.
I also use Flourish products.

[BigDaddy]

The point in a substrate heater isn't so much to heat the tank as it is to aerate the substrate.  Because of convection, the warmer water naturally rises through the substrate, allowing for better circulation, less chances for anaerobic pockets and potentially bringing more oxygen and nutrients to the root bed than would naturally occur.

That being said, in the years of keeping high light planted tanks, my plant growth has been very strong without implementing a substrate heater...

[alacroix]

Busdriver-  What type of substrate heater do you use and how many watts.  Haveyou ever tested the difference in temperature between the heated substrate and the water column. If so, what were the results.

[busdriver]

Root Therm by Red Sea.
40 watts

And no I haven't done a test of the difference yet.

I've actually tested to see if it heats the tank and the answer is, No, it doesn't.

I turned the main heater down to 75F and the temperature is now 75F.

[loves mayo]

in my experience the sub heat creates water circulation in the substrate and roots which is beneficial to the roots as far as nutrient uptake.the more vigorous the roots grow the less algea blooms and  cleaner water also.the 2 degree temp difference in the substrate is very important to the plants.