offset the volume scale 0 line display by a given amount

[TriggerNinja]

Need to set lower study volume scale to display bubbles that display below the candles/0 line..

I am playing with creating a volume percentage change display from candle to candle. The cleanest way I've found is to display the bubbles below the volume candles.
The problem I am running into is they display below the zero point on the right side scale. I can manually adjust the scale so they show, but that is rather inconvenient.
I have fooled with commenting out the zerobase declaration, even tried to create a hidden "dummy plot" to imitate a plot below zero but I must be missing something.
Does anyone know of a way to offset the volume scale 0 line display by a given amount?
This is what the display looks like with it manually moved up to display the bubbles.
Anyone have an idea??

 

[SleepyZ]

Need to set lower study volume scale to display bubbles that display below the candles/0 line..

I am playing with creating a volume percentage change display from candle to candle. The cleanest way I've found is to display the bubbles below the volume candles.
The problem I am running into is they display below the zero point on the right side scale. I can manually adjust the scale so they show, but that is rather inconvenient.
I have fooled with commenting out the zerobase declaration, even tried to create a hidden "dummy plot" to imitate a plot below zero but I must be missing something.
Does anyone know of a way to offset the volume scale 0 line display by a given amount?
This is what the display looks like with it manually moved up to display the bubbles.
Anyone have an idea??

View attachment 24354

This might help give you some ideas

declare lower;
plot Data = volume;
data.setpaintingStrategy(paintingStrategy.HISTOGRAM);
data.assignValueColor(if close>open then color.green else color.red);
plot zero = 0;
plot bottom = -average(volume);
bottom.setdefaultColor(color.black);
def diff =(volume-volume[1])/volume[1]*100;
addchartBubble(!isnan(close), zero, round(diff,0)+"%", if diff>0 then color.light_green else color.pink,no);