Question on volume

Hi all,

Unlike stocks and shares the currency market doesn’t let you see the depth of market so it makes it hard to understand if your lot sizes can be filled at a certain price.
I am developing an EA (that uses Renko charts) The system has to triple up every time it
loses so it can go from betting 10 standard lots to having to place 50 lots very quickly.
My question is : does a currency pair like the GBP/USD have enough volume (and liquidity) to accommodate a placement
50 lots without dramatically altering the market ? Or would an order of 50 lots just go through without a blink because there’s so much volume (as I’ve been told)
For example at the moment the ask price of the GBP/USD is 1.33060 and i want to buy 50 lots for the ask price. Is an order as large as this going to strip through many market depth levels and raise the price to 1.33070 for example ? Or is there enough volume usually to accommodate a buy order of 50 lots and the ask will remain at 1.33060 or there about ?
What is the required volume for example to make the price go from 1.33060 to 1.33061 ? I don’t have a clue as unlike stocks you can’t see market depth.

Thanks for your help.
Greg