mold in my tank

[chris lock]

i have a mexican red knee tarantula which i've had for about 2 years.
i checked on him today and i notice a patch of mold in the back of his tank i removed him from the tank to inspect it more and when i lifted the log he has it was quite moldy. i thought the best thing to do would be to clean out the tank and log and put fresh substrate in as luckly i had some

the humidity is around 55 and the heat mat is on all the time. i didn't have this problem last year. im new to keeping tarantulas do you think the humidity was too high as it dropped below 45 last week and i may of sprayed too much water in to the tank to bring it back to the right level.i check humidity levels every couple of days and try to keep it around 55

i think the last time i changed the substrate was about 6 months ago. is it right only to do it once a year as felt a bit bad as was webbing all around the log and i imagine the little fella is gonna be pretty annoyed now.

i thought it best to clean the tank as im sure mold is not a good idea in the tank

any help much appreciated

chris

[Peter Roach]

The mold in itself wont hurt your smithi but the high humidity wont do it a lot of good.
I find it hard to understand how you have mold growing with humidity of 55%.
At a guess I would say that you are using one of the dial type hygrometers ?
Want some advice ?
Throw it away !!!
The dial types are notoriously inaccurate and are not worth the space they occupy.
Personly I wouldnt even bother with checking the humidity, I would (and do) just pour in a small amount of water (about 10ml) into one corner every few weeks.
I have a few different juvenile Brachypelma's (10 smithi, 30 emilia,18 vagans, 17 boehmei and 2 schroederi) that i have raised from 1cm slings and this is all I do in their tubs, they have grown and molted on a regular basis with no problems.
I havent a clue what the humidity is and dont intend to check either but from previous experience, I would hazard a guess that my spider shed has an ambient humidity of around 40%

[Tom Forman]

wood is prone to rotting and getting mouldy over time.

You should try and keep the side of the tank you have a wooden log on completely dry to try and prevent this happening.

With a smithy, a waterbowl in a corner is enough for humidity.

If you really are worried about humidity which I was too when I started then I would highly recommend drying out the enclosure completely for a wek or so on a monthly basis, then keep it slightly moister again. This will kill off any mould starting to grow and will not harm your spid at all.

[Peter Roach]

Here are a few pics on how i have my Brachys which seems to in constrast to how some members keep theirs.
This method does and has worked for me for many many years (from memory from about 1979-80)

[Peter Lacey]

Little bits of mould are often signs of food remnants and a good reminder to remove these.
Mould as you describe is likely to be too much moisture in the enclosure. You need to cut back on your watering and improve your ventilation. Your B. smithi comes from Mexico where the soil is rather dry. As Peter suggests the humidity argument is worth chucking out, most Ts will adapt to humidity levels that differ from their natural habitat, and maintaining relative humidity is no easy task. IMHO fluctuating your humidity is likely to cause more stress to your T than maintaining an ambient level with a simple water dish.
As for cleaning the substrate this should only be necessary on a surface level - remove dead items, wipe poo off the glass and you're sorted. No need to replace the substrate unless its looking particularly dirty. One prominent member of BTS declared he hadnt cleaned his substrate for 6 years!

[matthew spooner]

like tom has said, wood is very prone to rotting. the best thing i find is to get my own wood. i use bark from a fruit tree, which was recommended to me as the best thing a couple of years ago, luckily i have a plum tree in my garden so i have a constant supply. i bake it then hey presto i have a brilliant hide. the bark you buy in the pet shop are meant to be used for things like hamsters and arnt really ideal for the conditions which arise in a T enclosure