[Bryan]

Hi Randy:

On occasion I use the product THORO Waterplug to cement rock together and to mount frags. The only problems I have ever encountered is a short lived diatom bloom. This is the list of "ingedients" from the MSDS.

Ingredient Name PORTLAND CEMENT (70-75%)
Ingredient Name SILICA, CRYSTALLINE QUARTZ (25-30%)
Ingredient Name CALCIUM HYDROXIDE (0-5%)
Ingredient Name CALCIUMCARBONATE (0-1%)


While at Home Depot the other day I noticed a product called DAP WaterPlug which is also a hydraulic cement. From the MSDS it has the following. Would you consider the fused calcium aluminate harmful.

01 Hydrated Lime 39445-23-3 1.0-5.0 %
02 Portland cement 65997-15-1 40.0-50.0 %
03 Fused calcium aluminate 65997-16-2 20.0-30.0 %
04 Crystalline silica 14808-60-7 20.0-30.0 %
05 Calcium sulfate 7778-18-9 1.0- 5.0 %


Thanks