300 gallon holding tank fitting and black water valve height

buying a 2015 35' big horn - model 3160 .... first time RVing.... getting a new roof on it....the black water valve bottom edge is 12" off the ground. the holding tank horizontal cap bottom edge is also 12" off the ground - see the attached photo. will have the septic company drain from one of the vertical caps on the holding tank.... so, my question is if both are 12" off the ground is that good enough for draining my black water? or should I drive the rig up on 2" to 6" ramps so the black water valve is above the holding tank horizontal cap that I'm going to drill out and connect a permanent rubber hose to with a bayonet adaptor?

If I raise the rig 6" I was thinking of creating wood ramps... see the attached photo.

or should I use a macerator pump?

any advice would be appreciated.
 

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Hollandt

Well-known member
buying a 2015 35' big horn - model 3160 .... first time RVing.... getting a new roof on it....the black water valve bottom edge is 12" off the ground. the holding tank horizontal cap bottom edge is also 12" off the ground - see the attached photo. will have the septic company drain from one of the vertical caps on the holding tank.... so, my question is if both are 12" off the ground is that good enough for draining my black water? or should I drive the rig up on 2" to 6" ramps so the black water valve is above the holding tank horizontal cap that I'm going to drill out and connect a permanent rubber hose to with a bayonet adaptor?

If I raise the rig 6" I was thinking of creating wood ramps... see the attached photo.

or should I use a macerator pump?

any advice would be appreciated.
My thought is that the tank is typically higher than the dump connection in the RV and most contents will probably flow, but with the hose inlet and outlet the same you will have issues getting the remaining contents out of the hose. The ramps will certainly help this. I would also be a little concerned about solids settling in the 300 gal tank and whether they can be pumped out through the small opening. A macerator pump would help this but I do not see it as a necessity.
 
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