# Do plants get cold feet?



## MiamiAG (Jan 13, 2004)

OK, OK, don't kill me.  I am bringing up substrate heating. There have been studies (I think) that suggest that a temperature differential between the plants roots and the water column is a good thing. Does thing mean we should all invest in good substrate heating?


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## Phil Edwards (Jan 22, 2004)

I think substrate heating is only truly useful for layered substrates or those with no amendment at all. 

Modern "complete" substrates like Onyx, Flourite, and Eco-Complete provide a beneficial environment throughout where a sand/laterite substrate is really only rich near in the bottom layer. Providing a current of water to carry enriched water to that lower layer should help maintain a rich substrate as well as allow the plants to most effectively utilize the enrichment. The same logic applies to un-enriched substrates such as Kasselman uses. The flow from the heater cables helps transport nutrient laden water to the plants roots, in effect, enriching the substrate. 

If the plants are able to derive benefit from the upper layers that's comperable to the lower layers why would any flow in excess of that already provided by root uptake be needed? That's not to say that there could be no benefit from current in a commercial substrate. I've had amazing growth from crypts when grown in a tank with Flourite and using a RUGF. I wouldn't totally discount substrate heating, but I wouldn't call it necessary anymore either.


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## panaque (Jan 21, 2004)

I saw an article about this years back ( I think it was in TFH) and they said that in nature the substrate of areas where plants lived was actually warmer than the water they lived in. I believe this was due to decomposition of waste, although I could be wrong. UGF's are detrimental to root systems though as they pull water past the roots and stress them. It may also hinder nutrient uptake since they are constantly being "washed". In any event its not a natural process. I do know that lots of european hobbyists use substrate heaters and I think that it is helpful, although not necessary. I wonder if peat decomposition would raise the substrate temp. in the same way if layered at the bottom. Anyone know?


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## plantbrain (Jan 23, 2004)

Decomposition does not increase the temp enough to cause much/significant flux.

Flux is mainly what you are talkign about. 
The reason for temp variation in natural substrates in nature is thermal solar heating in relatively clear shallow water.

This heats from TOP down, not the bottom up.

You go to any wetland ansd stick your hand in there. You will see the top is warm, perhaps warmer than the water, depends on the water, flow rate, time of year and MANY other variables.
But you will find the temp decreses as you get deeper than the top inch or so. 

Same thing with sand on the beach.

As far as seedling heat trays, many places use these for starter cultures.
I think this is more along the lines at what you might want to consider and look at as far as this topic relates to aquarium plants. 

I've used cables for 10 years. I do not find they make difference in terms of both health and growth with any plant species.
I will say they do help with seedling culture of emergent plants such as lettuce etc. 

Regards, 
Tom Barr


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## MiamiAG (Jan 13, 2004)

Most major aquarium plant equipment manufacturers produce a substrate heating line (e.g., ADA, Dupla, Dennerle). However, other than the Optimum Aquarium, I have not seen any evidence that they are beneficial. Yes, I've seen George's work on this, but I still don't think they are necessary in a well planted tank.

Dupla's point was that it avoid compaction and helps to promote a healthy exchange between the substrate solution and the water column. I think this can be done by providing the appropriate substrate alone.

I used the Dupla cable system for years. It rarely turned on (I'm in Florida) for one thing. I didn't notice any differences in growth with my non-cable tanks.

Perhaps an experient is in order???


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## plantbrain (Jan 23, 2004)

I think the major makers are simply marketing and selling a farce IMO.

It's gotten into the dogma of plant keeping and rather than suggest something different and actually doing some real research, they just go with what the customers are asking for and willing to shell out big bucks for.

They are not researchers, they are businesses.
They have $ to make.

Why argue when you can make a buck?

Maybe if they paid me to shut the hell up I might not ruin their product arguements/reasons for buying these Same crap with light bulbs. 

I've had temp differentials of 10F in my tanks. Some folks have noticed slow downs in their tanks in winter in some regions, but this might be due to lower bacterial rates for remineralization which occurs in the substrate.

So rather than temp/cold feet/ not compacting the substrate, increased flow rates/redox etc.............it's just the bacterial slowing down, there fore add a reptile preset heat pad(some are set to heat no more than 80F etc or some come with temp probes and temp controllers etc) or a styrofoam pad under the tank I think you'd be hard pressed to show any difference even in colder climes.

Going from sand/laterite mix with heating cables to flourite alone was a huge difference in improvement, this told me right away one thing.

Cables were NOT the reason for the great improvement in plant health, it was nutrients/bacteria/porosity of the substrate.

It had nothing to do with the heating cables.
I sold all my cables soon there after.

I've bugged George for years on this issue.

Regards, 
Tom Barr


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## MiamiAG (Jan 13, 2004)

plantbrain said:


> Cables were NOT the reason for the great improvement in plant health, it was nutrients/bacteria/porosity of the substrate.


I could not agree more. 8)


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## HeyPK (Jan 23, 2004)

Plants actually move the water in the substrate. They have an active transpiration stream, even if they are submersed. See the article by Ole Pedersen at the Tropica site, Gas and Water Transport in Aquatic Plants. 
http://www.tropica.com/default.asp.


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## Sir_BlackhOle (Jan 25, 2004)

I always thought the main benefit of substrate cables was to allow you to keep the substrate healthier longer, so that you could keep a tank up for many years without having to tear down the tank. Im still a newbie and this just comes from reading articles online, so let me know what you think. Does flourite or laterite/gravel substrate offer the same supposed longevity that the heating cables do?


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## plantbrain (Jan 23, 2004)

I've had fluorite substrates in both non CO2 and CO2 plant tanks for close to 10 years now(wow, flourite's been out that long? I must be getting old).

I don't think a substrate ever "wears out". Even a small amount of iron should last for decades.

I suppose if you use ther substrate as the source of macro nutrients, soil based tanks etc, then it run out if you did compensate by dosing the water column.

Generally, these additions help start off the substrate in the beginning(cables, iron etc) and enrich the substrate some by bringing waste and organic matter down there.

But adding mulm, peat to a substrate starts this off immediately.

One of the ways I learned how to set up a planted tank was to have a bunch of fish in a fine sand tank with 4" deep and wait for 1-2 years.

Screw that, I vacuumed a tank at the LFS I worked at and added the mulm. It did okay from the start and certainly leaps ansd bounds better than a sterile tank sand.

RFUG did better.
Cables did a hair better than RFUG.

Regards, 
Tom Barr


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## Raul-7 (Feb 4, 2004)

Cables would only be helpful if you used substrate additives covered with gravel that has a really low CEC...so with all the new substrates out there with high CECs, cables are becoming a thing of the past!


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## aquaverde (Feb 9, 2004)

I would only use substrate cables if I couldn't grow anything without them. The frustration incurred the first time I transplanted anything with a root ball would be the end of the cables for me. I won't go into problems they create in warm weather.

I have a 10 gallon on an iron stand under another aquarium. It's about 2 inches above the floor in a house with the thermostat set at 65 in upstate NY and this has been the most brutal January I have seen since being here. The air stratifies somewhat, the floor is not up to 65 by a stretch. The plants for sure have cold feet, but this tank will grow anything I put in it quite well. It is about 2" of quartz gravel with 10% Flourite mixed in over about 2" of Profile, amended only by mulm produced in the aquarium. This is by no means a scientific experiment, but it's more than enough to keep me from ever giving substrate cables a second thought.


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## hubbahubbahehe (Mar 29, 2004)

I would like to add my 2 cents. There's so many other better uses that your money could go into... For example, lighting and pressurized co2..


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