Epson printers and ink question

I am looking into buying an Epson printer with the fallible ink wells.  However, some places sell a printer that uses a 500 series ink and others use a 600 series ink.  WalMart today had a 500 series printer but only 600 series ink bottles.  My question:  Can you use 500 series ink in a 600 printer and vice versa, 600 ink in a 500 printer.  The ink all comes in the same color bottles

don't know the answer but 500 series ink is at Costco, Mercado Libre Mexico and probably Amazon mx. I have an Epson L5190 that uses it.

I'd never buy a fallible printer - who needs more mistakes! OTOH, I have a fillable one I love. 500 series.