Hey guys. I have a question regarding my
Tarantula's substrate. I am using palm peat, for
me it works best. You get a fair amount of one
brick, it's cheap and holds humidity pretty well...
Maybe a bit to well. The palm peat in almost all my
tarantulas enclosures are bone dry and yet the humidity is always above 80%.
Why???????????????????

Hey Ryan,
Consider that of you have made your peat from a brick using boiling water, the dry peat is going to hold a lot of that boiling water which will obviously evaporate as steam. 80%+ is a fair amount of humidity to expect from freshly made peat.
If you want to get the humidity levels down dry adding more ventilation to the tanks or let the fresh peat cool and dry out slightly before putting it in the tank.
Also consider the tarantulas personal preference. C. cyaneopibescens, most brachypelma's and most African species will need lower humidity and your Haplopelma's, Tapinauchenius', psalmopeous and the other tropical T's will need higher humidity.

Just a tip: microwave your fresh peat to sterilize it. It'll help in the long run

Well you see thats the thing. Everytime i dissolve a brick, i put it the oven and bake it until it's bone dry. My 3 of my P. Regalis's enclosures are dry as can be and yet they molt without a problem. Same with my T. Apophysis and i know high humidity is a must for them. My humidity meter always reads 99%. The only time it goes down is if i open the lids or remove those white plastic vents.

@Ryan66, i use palm peat bricks as well been, been a user for 5 years now.... its great stuff.... all i do is boil the kettle and pour 2.5l of boiling water over the brick and leave it for about 3 hours to cool down... then i take the damp substrate squeeze out excess water and put it damp peat into all the spider cages regardless of the species... in about 2 or 3 weeks the cages will dry on there own... no need to go and dry it in the micro wave/oven (Panama:Just a tip: microwave your fresh peat to sterilize it. It'll help in the long run) this is true .... Just make sure your cages have good cross ventilation, I TRULY BELIEVE VENTILATION IS KEY TO KEEPING ANY SPIDER HAPPY AND HEALTHY.... Are you sure your humidity meter is not broken? Always go for a digital reader over those rubbish exo-terra plastic watch looking ones... they very inaccurate... Also I take it you you using those pet shop spider tanks? with the small white air vents.... those cages in my experience are crap... they look nice but they are terrible at ventilation... they should be called stagnant boxes with a 100% guarantee to grow mould and never give your spider nice clean air.... Rather build you own, buy plastic and put your own ventilation in, or kindly ask a forum member to build you a good spider tank... Most Tarantulas will be very happy with a bone dry desert tank, as long as you have a good size water dish and keep it full of clean water 24/7-365...

I don't even microwave my blocks or use kettle water, I just use hot or cold water from the tap and Bobs your uncle.
If I wont to dry it out I put it in the sun on a table and it dries it out in a couple of hours.


I think your Hygromator is broken, my substrate is moist and I have a water dish in my one tank and the humidity is only sitting at 80%.

Ryan66 wrote: ...The palm peat in almost all my
tarantulas enclosures are bone dry and yet the humidity is always above 80%.
Why???????????????????

Your humidity gauge is either broken or just a piece of junk? The first thing to doubt is the humidity gauge!