@Groat21
Well, If your run during the whole year..yes you should re-use it till 3 times maybe..
But if u run 2 times per year for example..for your personal use..you dont need to replace it in my opinion..
I personally run 2 times per year so i buy new coco every time..just boring to cure it after the usage..
If you mean temps of the water you put in..i personally, after i water, i put the next day's water in the buckets in order to reach the room's temperature (about 20c) and let it in the room till the next watering..i prepare the solution when the water is at the temperature i want and i iriigate it..and i do this cycle again..every single day!
If you want more info about coco..TAKE THIS:
COCO COIR:
1) You feed EVERY WATER and you MEASSURE the RUNOFF EVERY SINLGE TIME and you want the coco ALWAYS WET..there is NO lifte test and stuff like soil..ALWAYS WET..
2) If the EC of your run off is 0.5 HIGHER than what you PUT IN, then you must water PLAIN PHED WATER and measure the run off AGAIN!
If its doesnt go down the first day of plain phed water, give it again plain phed water the next day..
When the runoff goes where you want it to be you FEED IT AGAIN and you repeat the process(feed measure feed measure feed measure) until the EC of your RUNOFF is 0.5 higher than what you put in.
This is the way you adjust and stabilize the EC of you medium where you want..
What you must care about is the EC of you media..not the EC you put in..but what you do you must do it carefully.
3) About perlite i used to use it but i stopped since i start reading and learning..Where there is perlite there is also oxygen..where there is oxygen there are no nutrients..so to have plenty of oxygen is not a good idea..you have oxygen from the fabric pots and from the material COCO COIR which is much aeriated..so perlite is pointless on my opinion. So i stopped use it..
4) About equipment in order to measure the run off and you have many plants(over 1, because you cant do this as many times as the number of the plants) you should do it holistic..that means you should buy a tray..put something little from bellow of the one side in order to make it have flooring to you so you can take it easy from there, and you will have a run off with the AVERAGE level of the run off..that means that a plant maybe eats more than another..especially if you use different kind of strains,.so you must see the run off holistic but you also take a look on them individually..now if you can lift them up a little bit from the surface of the tray it will be good..if not there is no problem..
5) You give it solution until you have 20% run off..but be carefull not more cause you ''flush'' what the pots already contain..also be carefull because the water doednt run off immediately..maybe it can take a couple of secs to a couple of mins..based on what coco is used..
6) Additionally you must give it once per week cal mag because it doesnt hold it during the feedings and waterings due to this 20% runoff..
7) ABOUT FLUSH: this is a personal opinion..based on strains..AS A RULE OF THUMB u want to flush it for 1 week..so when to start depends on the strain..this is another issue..well you must flush it BY MY OPINION 5-7 days..
I personally w8 to see it start apper AMBER HEADS and i FLUSH IT STRAIGHT DOWN IN ONCE WITH FLOWLESS FINISH OF ADVANCED NUTRIENTS 2ml/LITRE to the EC of the tap water in a day..After this i give it PLAIN PHED WATER TILL HARVEST!
I wish i help you bro!
Cheers!