Ongoing Diatoms, how to resolve?

[Bengals888]

Hi,

I have the IM 25 lagoon fusion AIO. Caribsea sand, about 1.5”. Tank is about 2 years old now.
Lighting is AI Prime HD. CPR Aquafuge2.

From the start, I have used the RO/DI Buddie. It always shows TDS until the DI resin went out.
After a year, I replaced the filter, added one stage of BRS DI. Now I added second stage BRS DI.
I kept the buddie unit since it is compact size, only so much space in a one bed room apt. kitchen.

I understand it is related to sillicates in the water. No matter what I try, I always get diatoms
covering the sandbed. I don’t think it is dino since my 2 conches clean the sandbed each night.
No dead snails.

However, the diatoms cover the sandbed again daily, conches working at night, lol

I’m going to take down this tank eventually since I’m dealing with hydroids so I don’t want
this diatom issue in new tank.

The dual BRS DI resin should suffice in removing all sillicates?

My sand bed is also clumping, is that normal?

 

[Coralreefer1]

Resin should work at reducing silicates along with water changes. Sand clumping is probably a direct result of calcium precipitating from a high pH. Low magnesium and elevated temperatures, ferric ions and alkalinity can also spur supersaturation of calcium carbonate.
These can cause calcium carbonate to accumulate on pumps, heaters, sand and glass.