Well thankyou for the additional information. you do have some bio load with the animals you have there so some supplementation is most likely in order. The best way for me to answer your question is to simply say to do full water parameter tests and add to your system what is lacking but but investigate so you know why it is lacking. if your system is improving, look at the helpful articles test and tweak and the beginners articles, as there is a lot of information there that we all could revisit from time to time. if you are still not satisfied, I would recommend you consider this as a 1st method to increase your water quality, for salt water changes add 1/4 the recommended dosage of an ro water reconstitution mix prior to mixing in the salt. continue to do water changes weekly, watch your additives when starting to add the reconstitution mix (such as OSMO Prep Marine by Kent.) so you do not over dose something. if this increases your alkalinity, buffer and ph performance, then continue each month increasing the reconstitution mix and cut back on the other additives until you get to full dosage of the reconstitution mix at which time you should be able to control your water parameters by water changes only. make changes slowly and in small increments so you do not shock the system. hope this helps.