Help with alkalinity, noobie question!


New member
Hi, sorry but very new to the hobby and hoping for some insight. I apologize if this is more info than needed about my tank, but I figured too much was better than too little!
I have an 18g saltwater cube, I've had it a little over two months now. I stocked it with live rock and live sand initially, and it went through a very brief ugly phase then seemed to have stabilized nicely. I have only ever used water from my LFS. I have a clownfish, an azure damsel, two cleaner shrimp, several turbo snails and some nausarrius snails, a mushroom coral, a gsp coral, and a sunflower zoa. We haven't added any new creatures to the tank in at least two weeks. I feed every other day, as advised by my LFS, 1/4 frozen cube. The water is clear and beautiful, I have minimal algae, and my fish and corals all seem to be happy and doing well.
My question is about my KH. It consistently tests 80 mg/L, which my understanding is that this converts to 4.5 dKH. I have two different brands of test strips and they both always read the same. My ph is fine (8.4), I have zero nitrites and <10 nitrates, usually 0. Everything I have seen suggests I should be aiming for a dKH of 7. Given that my other parameters seem ok and all tank inhabitants are doing well, should I be chasing this ideal dKH number and adding a bunch of bicarbonate, or leave well enough alone? The interesting thing is that I tested the water I'm getting from my LFS and it's also at 80 KH (4.5 dKH). Its an extemely well known saltwater fish only LFS so I'm assuming they know what they're doing, and I hesitate to mess with the water I'm getting from them in case I end up killing everything, but I'm also nervous that my dKH is SO much lower than what people say to aim for. Thanks in advance for any advice you have!
I have two different brands of test strips and they both always read the same.
Welcome to Reef Central.

I'm not a fan of test strips. I use a Hanna Alkalinity Test Kit.

Agree with John test strips are not reliable. I prefer Salifert test kits and use a Hanna checker for phosphates.
I would have to agree, I’m thinking the test strip has an error. Have you had the LFS test their water and/or your water?

Also Welcome to RC!
Thanks everyone for the help. I'm going to take some water to my LFS to test while I'm waiting for my new test kit to come in!