Quintrix wrote: ... Have you seen your spider drinking water? What species and size was it? ...
Yeah. Hundreds of them. All species, even
Avicularia and
Poecilotheria.
Quintrix wrote: ... AT the moment I only have slings - about 2 - 7cm
Lasiodora, Brachypelma and Grammostola
Up to now I have not supplied any dishes with water and would spray about 1/month. How important is this?
Spraying (a.k.a., "misting") is
SSSOOOooooo 20th century! We have much better ways of maintaining an artificially higher relative humidity in a tarantula's cage now. Read
Relative Humidity
.
Here is a short essay on caring for tarantulas as they age and grow. (Soon to be turned into its very own webpage on
Spiders, Calgary
.)
CAVEATS: Note that the following rules of thumb apply to nearly all tarantulas except a few obligate swamp dwellers, and to the arboreal species, and those are addressed towards the bottom.
BABY TARANTULAS: Those younger tarantulas with a diagonal leg span (DLS) of about 1.5" (3.8 cm) or less should be kept in a relatively closed container that heavily restricts ventilation. The substrate should be kept slightly damp. All this maintains a constant, elevated (but not excessive) humidity. Do not mist; instead, reread the last few sentences carefully. Do not spend a lot of time, energy, effort, or money on fancy containers. Like humanoid babies, these will outgrow their containers soon, thereby wasting all your finest efforts over and over again.
SPIDERLINGS TO ADULTS: Those younger tarantulas with a DLS of about 2" (5 cm) and larger should be kept in cages with dry substrate and supplied a water dish with clean water. Keep almost all of these as arid species. (See the exceptions below.)
TWEENS: Those tarantulas BETWEEN the aforementioned two sizes should be gradually acclimatized to a dry cage over a period of 2 or 3 molts. Gradually allow the container/cage to dry out, but be very sure to supply a water dish with clean water. You're gradually removing the higher humidity and substituting a water dish as the primary water source. In response, the tarantula develops a thicker, more impervious waxy layer to prevent excessive water loss from its body. All it needs is a little time to adjust.
Note that many tarantulas from semi-arid and arid places like the American Great Plains and the Kalahari Desert can make this transition much earlier in life than these recommended times. But, it does them no harm to wait a little longer either.
SWAMP DWELLERS: These are tarantulas like the species of Theraphosa, Ephebopus, Hysterocrates, Megaphobema, and a few others. These do not have the impervious, water retentive exoskeletons of the other tarantulas and require a constant, high humidity. Keep these in "baby" style cages for their entire lives, adjusting for increased size of course.
Enthusiasts are discovering that wild caught "swampers" will gradually develop a somewhat greater resistance to slightly drier conditions if the transition is done slowly and over an extended period of time. And, those swampers that are bred in captivity fare much better and can tolerate drier cages much better than their wild caught brethren.
ARBOREALS: Wild caught arboreals (assumed to be adults), particularly members of the genus Avicularia often fare poorly when first brought into captivity, partly because of "shipping shock" and partly because of the sudden change in environmental conditions. To combat this, they should be initially set up and cared for as babies for the first few weeks (initial recovery period), then quickly switched to a "Tweens" care regimen (secondary acclimatization period) for the first one or two molts. Thereafter keep them as adult, arid tarantulas but maintain a slightly elevated humidity by slightly restricting ventilation. Always supply them a water dish. (In the middle of the night as they hunt for food they'll pussyfoot down to the water dish and take a sip. And being sound asleep, you'll never, EVER know it happened!)
Captive bred arboreals (assumed to be babies or very young spiderlings) usually do not suffer the acclimatization problems that the wild caught ones do, but sometimes suffer shipping shock from bad treatment during transportation. When first received they should be kept as babies (see above) for two or three weeks, then they can be quickly changed over to whatever care regimen is appropriate according to the schedule given here, depending on their size and age.
Lastly, the three genera you mention are all cared for as arid species as adults.
Hope this helps. Enjoy your 8-legged little darlings!
Shaun