you kinda have but 2 choices,first is use a little woodash depends on size of pot to how much,to raise your ph a little ,wont to do this in small increments,it is same as lime which brings you to a neutral ph of 7,i use ash and do a spoon at a time,checking each addition and stopping at 6.5.
or just use the 6.5 ph all the way threw your grow,feeding 6.5 gives what it needs,and later down road depending on if you over feed and build salt up in the soil the ph will jump up and then you will have to adjust your ph going in to buffer what the soil holds,okay so if this is say ocean forest you want to come up .8 to bring you to a 6.5 soil ph your in a 1 gal pot,so i wood start at 1 tsp of wood ash and scratch it in,right before next watering do a slurry see how much the tsp raised the ph,you dig,5.7 is in the range of coco so if you just got it to rise to 6.0 you will be good in soil,6to7 is soil range,why wide open ,because of salt buildup later down road could go either way if you dig,so next run check soil first,if you have any extra soil that is in that pot,fill a 1gal pot with it and do testing on it instead of messing a plant up if you do,if you get that soil in the 1 gal right ,you could up pot to the soil that the ph is right.
that plant dont look to bad ,you caught it in time and you sure could transplant it in better ph soil this young