Alkalinity issues

[Anitaw]

I am not new to this hobby, but last year I got a larger tank, 40 gal aqua-top. I have soft corals and SP, along with 4 fish and some brittle stars that came in the rock, and some snails as CUC. I have a hard time getting my alkaline up. Ranges 6-7, calcium 376, ph 7.9 nitrate 1, nitrite 0, phos 0.03. I top off with kalk and sometimes add 8.4. I note some detritus on top of gravel, I have good tank flow, do feed phytoplankton, reef roofs, fuel and reef AB, alternating to do 3 times weekly, along with feeding brine shrimp to Fish 2-3 times weekly. I was a cleaning fanatic with my tank, 5 gal water changes and gravel vac every week. Have stopped, only 4 gal water change every other week.
any help/suggestions appreciated!
Thank you

 

[Anitaw]

Find out what kits and method they are using to do these tests for you.
There is such a thing with bad RO and salt water purchased and not saying it is but have it tested when you purchase again for: Nitrate-Phosphate-CA-ALK -MAG and even salinity. Im familiar with all the WI stores as I am in Sheboygan area.
You may however have answered your question to why your alk is low. You mention hubby has a 14 gal tank using same water and has less corals and alk is good on his tank.
As I had mentioned- Consumption- You have more corals and in turn are utilizing the alk and CA for their needs showing dropped levels.
This is safe- drop a teaspoon of normal baking soda per 10 gals into the sump next 3-4 days. Watch what happens yo your alk levels- They will slowly climb

Great thank you, I will try that. Yes, I’m in SEWis. Thinking of doing my own water. But thanks again.

 

[G Santana]

Welcome to the Reef