Hydroguard is bennies and only bennies right?
I doubt it affects PH in a relevant manner for this case.
Usually Calmag products have Iron traces I think but so does the micro from GHE Tripart.
Seen many recomendations to use this order: Silica -> High Nitrogen Content -> Low nitrogen content ->-> Bennies/Hydroguard
Note that every mineral product will affect the beneficials in a bad way so I think it's best to not add them all together. Specially in a Hydro setup. If you can wait a bit and let the nutes react for some time before adding the Bennies is best.