How to keep your telescope Fungus free?

[michael]

hi,

I think some ppl getting problem with fungus growing on primary mirror or corrector plate. Telescope like SCT can't place inside the dry cabinet. pls write your comments.


Thank you
michael

[Clifford60]

Dry cabinet has different sizes or even custom made, I believe you can find one to fit your requirement, bottomline is the price.

I think 8" SCT can easily go into a 100l dry cabi by removing some or all the shelfs. The approx internal height for 100l is 680mm while 160l is 1140mm. In the worst case, convert your home shelter room into a giant dehumidifier room (cheaper than the bigger dry cabi) but you need to clear water once a while.

[acc]

hi,

I think some ppl getting problem with fungus growing on primary mirror or corrector plate.

Hi Michael
Sadly, its not 'some' but 'most' optics eventually gets fungus on the optics due to our humid environment... If yours is a fork-mounted SCT, than I guess the most convenient way would be to dehumidify your whole room like what Clifford suggested. Or perhaps get a portable dehumidifier and store your scope in one of those gigantic plastic storage containers sold in hypermarts.

[mySG_jy]

any one has idea what is the humidity % that we should be keeping to control the fungus? 50%? 40%

[rlow]

Michael, here's a few way:

1. dry box with silica gel (with or without hygrometer)
2. dry box or cupboard with heater element installed
3. electrical dry cabinet of various sizes - 100 litres can fit in a C8 ota
4. dry cupboard or store room with dyhumidifier installed
5. air-conditioned room
6. left in an airy well-ventilated room with some sunlight exposure - this works for some people in some locations (but not Bukit Batok)

[rlow]

any one has idea what is the humidity % that we should be keeping to control the fungus? 50%? 40%

The recommended max. humidity for our kind of equipment is 55%. Unless you get a premium model with precise humidity control, you have to allow for 5% error due to the dehumidifier and another 5% due to the hygrometer. Hence I set at 45%.

[mrngbss]

Clifford is right about the price. A 400 litre can put a C11 with extras very comfortably, two C8s, and many accessories. But it costs.

I put my lens cell in the dry cabinet and keep the OTA somewhere else. But this is only for a surplus scope which I seldom need to use.

I use humidity at 50%.

[michael]

cheaper way.

just buy those big size plastic box with cover. put some silica gel inside.

this is not so expensive and can put big size telescope too.

how about the hmdty level?

can u talls me silica quantity require for 20" X 12" X 12" Box?


thank you

[weixing]

Hi,
The most easy way to keep your scope, eyepieces and lens fungus free is to use them often...

Anyway, light and air circulation are very important. Fungus will grow in a damp, dark and dirty place with still air, so the best is to keep reasonable air circulation, periodic sunlight exposure, inspect periodically and use them often.

By the way, if you decided to put your scope, eyepieces or any optics in the dry box or dry cabinet for long time storage, remember not to put on the lens/telescope/eyepiece cap. The fungus might still grow if you put on the cap as the water vapour is trap between the optics and cap even you put in the dry cabinet... I once got a Nikon lens which I put in a dry cabinet with the lens cap on and after a few month of unused period, fungus grow happily on the lens...

Have a nice day.

[Clifford60]

cheaper way.
just buy those big size plastic box with cover. put some silica gel inside.
thank you

Since you spend so much on a scope, don't save a couple of hundreds for a digicabi. In the past, I used to keep my cam in a cam drybox with silica gel, months later, fungus grew.

Furthermore, you need to maintain the silica gel (depend on how often you open the box) or replace them. It is really pain in the neck to maintain it and long term cost may not be cheap. Digicabi typically use 4 or 5W, so to use 1kWh (~$0.20), it is about 10 days.