Please help, what is wrong with my Cacti ( PICS )

[jack t]

Hi, i bought 3 cacti from ikea 4 years ago and love them, now one of them has white dots and is turning yellowy brown.
They are kept in doors by the window
please help me and what shall i do?

water them, don't water them, too much sun ect.

thanks

http://s1154.photobucket.com/albums/p523/helpmycacti/

[hoteidoc]

Looks grim, probably rot! Soil looks very rich, too. Remove from pot & check roots & neckline. Others will probably jump, but looks like cut-thru with sterile knife. Cut slices, working towards tip to see if if any of it "clean", i.e. healthy, to dry & save as a cutting. I'd be cutting potting mix with @ least 50% coarse grit, Turface, NAPA/AutoZone, vermiculite, something...to reduce organics & increase drainage.

[luddhus]

Rot is not my primary suspect, I think it looks more like skin damage from sunburn or possibly bugs. I would remove the plant from the window for a week and see if the brown patches spread before cutting anything.
I agree about hoteidoc's comments about the soil though.

[iann]

I agree. The plants look fat (and happy if you like fat green cacti ), but there is something marking the skin.

[TimN]

I get that occasionally and have always thought it was rust, a fungal infection. I spray with anti-fungal and hope for the best. Some species seem to be more prone to it than others, in my experience. I also believe it's transferable so I segregate any affected plants. Unfortunately the orange patches lose their brightness, but never go away. The damage is done.

[jack t]

Thankyou everyone for your replys, i will try that and hope for the best.

thanks again jack