I need help with my 20 gal

[Emma_fish]

So I have had this tank running for a week but I only had it half way full filter and heater where still on I have filled it up yesterday to the top and have bought two nitrifying bacteria’s which one is best to use and how do I do it I’ve never had a saltwater before to I’m a bit stuck with the cycling process and should I test it now ?
And do I need a refractometer if I got my water from the fish shop

 

[Wee Mad Arthur]

I cycled mine with actual real live rock but I recently cycled my freshwater tank with bottled bacteria and used these guides: (I did only use Seachem products though)

Guide: An introduction to cycling your tank

What is tank cycling? “Cycling” is the process of growing good bacteria colonies in a tank which consume toxic fish waste and convert it into less toxic forms. The process of cycling a tank can tak...

seachem.zendesk.com

https://seachem.zendesk.com/hc/en-us/article_attachments/360054680653/Tank_Cycling_Schedule.pdf