There are two camps of thought here:
1. Discontinue fish oil while using ArA as fish oil could potentially displace ArA. Therefore regardless of what time you dose the Fish oil, it could potentially have a counterproductive effect. I’d need to re-look at the literature on this.
2. Keep on using your fish oil supplement, just make sure it is as far away from the ArA as possible.
For me personally, I just discontinue using fish oil while using ArA. In the last 3 years, I’ve probably done 2 separate ArA runs for 50 days. So out of ~1,000+ days, ~100 of them were without a daily 2-3g EPA/DHA. Again, just my personal preference