For my 20 pound bottles it was 36 in the city it would last me about 2 months, no leaks
That's why I switched to dosing ballin salts saves going there to deal with them, I always keep 2 bottles to save the hassle of running out.
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360 gallon sps reef, 180 gal sump, bubble king supermarine 300, 4xmp40Wes, 2 x 6215 tunze waveboxes, 4 ghl mitras
360 Reef Tank