After weeks of reading decided to replace my deltec 1500 to a skimmer that is actually rated for my tank volume (approx 500l with sump).
Everything was going great with the deltec 1500 until about 1 month ago. Kept overflowing no matter what adjustment I did. After researching a fair bit about oversizing of skimmers (contentious) decided that this could be the reason.
clearly the deltec 1500 was oversized for my tank vol. however initially with the higher amount of die off / bio load, I managed to tune the skimmer adequately. Now that things are somewhat stable and perhaps