Desi it all depends on the ATR you are using. If you are using 1% risk per trade on 2 x 20 day ATR then you would need an account of @ 3000. As per the method I proposed.
The reason for this is so that you can as near as possible achieve the same risk over all pairs traded.
Small accounts like 500 will give heavy weighting to the higher volatility pairs because the minimum lot size is 0.01 lots and I'm talking Global Prime here.
As an example the GBPNZD has a 20 day ATR of 180 so your 1% stop loss would be 360 pips per trade. This is £5 per trade which means that you need a lot size of 0.002. As your minimum is 0.01 this means that you would be risking 4% per trade - £20. If the ATR increased to say 200 then you would be risking 5% per trade.
Even low volatility pairs such as EURCHF with an ATR or 51 you would be risking 2% per trade so you need an account large enough to accommodate all pairs that you intend to trade.
So a few high volatility trades going against you could get very sticky very quickly.
On top of the fact that your Margin would get eaten up very quickly.
A 3000 account is sufficient for a 20 day volatility of 250 pips. Were I ever to trade this live then the absolute minimum that I would personally use is 5000.
Have a play with this calculator and you will get a feel for the size of account that you need.
http://www.myfxbook.com/forex-calculators/position-size
Having said that TraderJoe is not trading his method using Daily ATR, I believe he is using 4H ATR and is quite different from my method hence the reason that you may be getting confused between the two methods traded but I hope that my explanation explains why I mentioned in post 1 why such an account size is required for such a method.