heat matts

Subject: Re: heat matts Wed May 07, 2008 9:29 pm

IME bottom heat is much better as it provides heat to the root zone.
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mmm spikey...

Moderator Joined : 06 Apr 2008 Posts : 354 Location : oz

I agree, but from a cost perspective a light globe is cheaper than a heat pad and thermostat

Age : 35 Joined : 26 Apr 2008 Posts : 181 Location : Cairns

In that case then use a ceramic globe - they don't blow, they can be thermostatically controlled and they have a much longer life.

Soil temperature is much more important to seed germination than air temperature (in my past experiences - though admittidley not with cacti). The soil temperature is more likely to be consistently higher when heated from underneath than when heated from above.

The thermostats are located on this page:

http://wehaveitall.com.au/store/index.php?act=viewCat&catId=29

You don't need to pay a fortune Smile

There's some good cheap ones there. Just remember though, you're playing with heat, so be careful.

Most of the accessories you would want are similar to that of reptiles (suprisingly enough).

http://wehaveitall.com.au/store/index.php?act=viewCat&catId=28

The aquarium idea is good.. but do not fill your aquarium with sand, use moveable seed trays and heat it from underneath and/or above.

Humidity is easier to control that way as well.

I really didn't realise how lucky I was to live in the tropics, high humidity, high winter temperatures... I live in the worlds largest terrarium Smile

So, option C - Move to Cairns!

Subject: Re: heat matts Wed May 07, 2008 9:37 pm

I think for anyone who seriously wants to raise rare cacti seeds, a heat mat is essential. That said, not everyone wants to propagate rare cacti.
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mmm spikey...

Moderator Joined : 06 Apr 2008 Posts : 354 Location : oz

Great idea.
Now you have me thinking about putting my globe under the plant trays in the aquarium for heated soil using light Smile

Subject: Re: heat matts Wed May 07, 2008 11:17 pm

I agree on the bottom heat. It is pertty much essential, but it depends how cold it is where you live. The low over night temp does not seem to effect germ but when the temp during the day does not get high enough the germ rate suffers. Also when buying heat mats be careful they can handle high humidity environments, at one point or another when cultivating cacti water is going to be spilt and I don't wanna see anyone get hurt Smile

I personally don't need a heat mat as I just germ my seeds on top of my metal grow stand. Due to the heat of the lights and the room temp the top gets quite hot. Old hot water heaters work great too.

Age : 35 Joined : 26 Apr 2008 Posts : 181 Location : Cairns

I assume the temperature lag in the soil is what keeps the soil much warmer over night - which is why the over night temperatures will have little effect providing we can get soil temps above 18'C during the day for at least 10 hours (though I can't confirm this is adequate for cacti, but it does suit a range of seeds).

Also - soil is more convective than conductive and a little radiation also. But most of the water/air in the soil is heated through convection - so underneath heating is far more efficient (think of a jug or a hot water heater and where the element is).

But because the seed is so close to the surface, surface temperatures will also play a part. So if it's -4'C above ground and a toastey 20'C below ground, I think your germinated plants will be a bit confused as well.

Daytime light hours also play a role in germination and survival - unfortunately I know little about this with cacti - and most plants seem to overcome this. But not all plants can.

Subject: Re: heat matts Thu May 08, 2008 5:39 pm

I took back my old mats today and the guy at the shop has
exchanged my old matt's for a

TPS 040:

Two tray heated propagation system with thermostat

The TPS 040 heated propagation tray holds two seedling
and/or drip trays. This 40-watt tray
comes with an in-built 0-40�C
thermostat for accurate temperature control all year round.

Dimensions: 670mm x 400mm

and picked up a TPS TOP

The TPS TOP Clear Top is a plastic cover, which sits on top
of a single size seedling and/or drip tray, creating a mini-greenhouse effect.
It has a 3-way vent system, providing further temperature and moisture control.
The TPS TOP can be used with or without the heated propagation tray.
Dimensions: 365mm x 300mm x 160mm

Pick them up on Tuesdays...

http://heatngrow.com.au/products.htm

were do you get your preferred propagating sand from?

cheers

afro

Moderator Joined : 06 Apr 2008 Posts : 354 Location : oz

Not yet giving way to technology, I raised the floor inside my aquarium and placed the light / heat globe under the plants - they are now getting sunlight through the window and bottom heating Smile

Age : 35 Joined : 26 Apr 2008 Posts : 181 Location : Cairns

Heat rises calycium... don't let em get too hot Smile

Moderator Joined : 06 Apr 2008 Posts : 354 Location : oz

I hear ya Slim.

Its only a 25 watt globe, just nice to give some warmth when the sun goes behind a cloud.

Joined : 02 May 2008 Posts : 92 Location : Bendigo Victoria

Hi guys, finding this post most interesting as I try to find a system that works until I can get a commercial made thermostatic controlled propagation system. picked up a couple of interesting perspex display units, with metal bases, they have hinged lift up sections and are a great size for fitting a seedling tray. not sure how I'll add heat yet, but the 25 watt globe sounds good. also have a water bed heat pad with thermostat that I thought I;d have ready for autumn sowings. hubby is making a base for it but it is still on his drawing board. any suggestions on using this type of mat. ?

Joined : 16 Apr 2008 Posts : 20 Location : A-Town

get a thermometer in there calycium and play with the setup until its about right.

Age : 18 Joined : 28 Apr 2008 Posts : 17 Location : Gympie

I bought heat cord for $40 and a thermostat for $70 (but they're for my reptiles =P )

I bought the thermostat off www.herpshop.com.au , they send the product and then they send you an invoice and you can pay for it once you receive it.

Joined : 26 Apr 2008 Posts : 119 Location : brisbane