Hey guys feel like a total dumass asking this but whenever I try to tune my guitar to drop d the bottom string gets unplayably loose...why?!? and how do I fix this?!?
What string gauges are you using? And are you sure you're not tuning down a whole octave? You should only be tuning the lowest string down one whole step.
Gibson RD Silverburst w/ Lace Dissonant Aggressors (SOLD)
Electra Omega Prime Ceruse
Fender Franken-Jag Bass

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Laney VH100R
Seismic Luke 2x12
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yep i'm pretty sure I'm just doin 1 whole note...cos I couldn't be arsed twisting a peg down a whole octave neway;p...sorry...not exactly sure what string gauge it is cos I didn't buy or change them...but I am usin a tiger clip on tuner...are these accurate?!?...just a thought...dunno...im not really a guitarist so wouldn't have a clue about most things
Can't speak for the accuracy of the tuner but for the issue you are having you are either playing super light strings or you are tuning the string way too low. A simple check for the tuning is in standard Tuning the low E string on the 5th fret should match the open A string below it, in drop D the 7th fret on the low E (technically now a D) string will now match the open A string.

If the tuning is fine and the string is still super loose then you need new strings that have a heavier gauge and will keep their tension at a lower tuning. Regular 10-46 strings would be fine for standard and drop D tuning.
I would find out what strings are on your guitar and go up one size if it feels too loose tuned down to drop D ...... or go up a size on the low E string only
I have an Ibanez RG421 with 9/42 D'Addario Superlights and even with that string gauge, the lowest string doesn't get "unplayable" when I tune to Drop D.
It's noticeable that my setup isn't meant for Drop D but definitely not unplayable.
Can you borrow a friend's tuner and try it with his ?