Are my SEP-IRA contributions tax deductible if I also contribute to a retirement fund?

I earn about 99% of my income from being self-employed, and as such I contribute to a SEP-IRA. Recently, I also started a teaching job at my local community college, where I only go 3 hours a week. Through this job, I was enrolled in CalSTRS, which is a teacher's retirement plan. It is neither a 401k or a traditional IRA, it is a defined benefit pension plan. I was told that because of my contributions to the pension plan, I can't get a tax deduction for my SEP-IRA contributions. I would much rather get a tax deduction for the SEP-IRA and not the pension plan because I contributed way more to the SEP-IRA. Is this accurate, that making contributions to the pension plan will prevent me from getting tax deductions for my SEP-IRA contributions?

posted