Archispirostreptus gigas, terrarium and care

  • Hi to all, my name is Eleonora and i live in Italy. At first compliments for this interesting and complete forum, it's a shame that i don't speak german.
    Some weeks ago a friend gave me a beautiful gift: five young CB Archispirostreptus gigas!
    They're long 7-8 cm (how old could be them?).
    In Italy there are few people that breed this millipede and infos aren't many about its necessity. So I asked and read, trying to do my best for them... but i don't know if I'm doing well. Hope you can help me!

    My A. gigas live in a tank (Samla Ikea) of 57x39x42h cm (65 l) with three holes (two lateral 9x9 cm and the last one large as the cover).
    Substrate (high 20 cm) is coconut fiber mixed with forest soil (cooked to sterilize), decaying leaves and wood, eggs shell. Set up includes barks, boughs with lichens, moss and broadleaf leaves.

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    Every day I give them fresh fruits and vegetables, dog/cat food or pond sticks, cuttlefish.
    I often nebulise water to keep the correct humidity: 1-2 time every day, especially now that weather is hot and dry (actual italian temperature is 30-32°C) and sometimes I wet the substrate directly.
    Lately I've noticed some little Diptera (long 1-2 mm... perhaps Drosophila? they're too small for photos ?( ) into the tank. I trying to remove them changing food often and putting outside a glass of honey like attraction, without success. What i might to do? sometimes i found leaves with mold, i wouldn't like that there was little ventilation and high humidity.
    What I'm doing wrong? someone told me that peat is better than coconut fiber, is it true?
    thanks for your time, hope that you understand my english :P