White Spots On Tank Harmful?

[mwood2]

seeing as I still cant seem to get the white stuff off my tank and I cant determine what they are and what can get rid of them (vinegar+baking soda, Toilet Cleaner didnt work) and no one can seem to find something that will work, would this stuff be harmful if I decided to start my fishless cycle now? and is there a chance if it would come off after water is in the tank for a long period of time.

Sorry for so many topics, If anyone can make final suggestion if this will work or any other thing that can take this stuff off? I touched these areas on the take and ots not crusty, it almost seems as if its part of the glass now since the tank has been sitting around for a long period of time before I bought it.

Also final suggestion is Pure Vinegar/Lemon or Bleach. Both have been shot down by people and I have tried almost everything besides bleach and CLR (think its toilet cleaner/unclogging liquid)

also does ammonia help this either?

 

[Syphoniera]

Hi, mwood2,
I strongly suspect that CLR would damage/dissolve your sealant, apart from anything else, such as the risk of residual toxins permeating plastic trim/silicone.
The white deposits will almost certainly be mineral deposits and harmless, if unsightly.
However, they typically are not visible once the tank is filled, unless very bad, and even if noticeable, do tend to very gradually reduce with time.
I buy a lot of second-hand equipment, and if vinegar and salt fail, do try bleach, but prolonged soaking in a strong bleach solution may weaken sealant as well.
I figure if that, and the endless rinsing required, fails to clean mineral deposits, that they are then unlikely to come off in water and are unlikely to harm fish.
Hope that helps.

(Edit - just saw other thread - guess CLR's safe. May I say 'ooops'?
Good, because I needed to...)

 

[saz326]

As a last resort, you could always try a VERY sharp knife blade. e.g. stanley blade. Gently but with good pressure scrape the mark off with the blade laying flat against the glass. (hold blade at aprox 45 degree to the vertical)

Has to be a fresh blade tho coz any nicks in the blade may cause scratches on the glass. Do not use the blade point.