Calcium can make your body absorb less tetracycline from the stomach, so the antibiotic may not work as well as it should. This is a minor interaction. To avoid it, leave a gap of at least 3 hours between taking Algae Calcium and Tetracycline Hydrochloride.
Little or no effect is expected. You usually do not need to change anything, but still tell your doctor or pharmacist about every medicine you take.