The burp hole just burps excess out beyond whatever level you drill the burp hole at. It self levels the amount of gas in a tube is all.
I think you did not add the suction cup on the side of the tube, the top heavy aspect is good when you add the suction on the side of the tube.
You melt it in there and clip the suction cup in, that holds the units very well to the side of the tank, the weight of the power head keeps it pressed down.
You are NOT suppose to use a catalinia powerhead(you can if you so chose, but I've never used them, nor suggested to), that was your own choice to force all that together.
Rio's are cheap and available, they work very well for this reactor and are 9$ on line.
Just in case, folks are to use an elbow inside the top of the lid, not a straight down attachment to the powerhead output/effluent side.
Most folks use a filter in conjuction with a powerhead/reactor, simply placing the out flow near the reactor solves any of that extra powerhead needed business to get the CO2 well mixed in the tank etc.
If you want to have more directional flow(If you use a filter, it's not needed), simply slap the end cap on the viewtainer on the end and melt/drill a 1/2" hole on the bottom of lower side of the cap etc to direct the outflow anywhere you want.
This is not brain surgery, it's simple and solving issues you may have takes a little fiddling and some simple solutions.
Many want to use other brands etc, that's fine, but you may have more trouble putting it together.
If there is something you like about one unit, and want to add it here, just ask, adding a cap is a simple thing, so is placing it in the flow of the filter etc.
I think many times folks hit their heads against the wall when there are very simple solutions, lord knows I've done that enough more than I like to fess.
I hate that
But it can do the same thing as those green plastic giant tubes they sell for CO2 reactors, never found them to do well myself nor a few stores that carried them here.
Regards,
Tom Barr