It comes down to volume, or a lack of volume. You need enough liquid to keep the heating elements covered while simultaneously pulling liquid down through the plumbing and pushing it up through the grain bed and over the top of the malt pipe. If you don't have enough liquid, you risk exposing the heating elements, which can burn them out and you lose control of heating the mash liquid. The shorted malt pipe requires less volume to pump through the grain bed while keeping your elements covered. And it only costs $98, which is 3.4% of the cost of the 50L system.
As a side note, I understand that, at 145 pages, this is a long forum to read. At four minutes per page to read, it works out to be roughly nine hours of reading time. But let's look at a simplified evaluation of the value of the information within the thread:
Assumptions:
- Buying a 50L SBM @ $3700 (including accessories, shipping & customs)
- If you buy the SBM and hate it and return it or resell it, let's say you lose $700 that would be the Bad Outcome Value (BOV)
- If you love the SBM, let's say you brew an extra 7 times a year, and let's put a value of $50 on each brew, and let's say we'll brew for the next 10 years. That equals a value of $3500 or the Good Outcome Value (GOV)
- If you saw a SBM online without a lot of supporting documentation, let's say there is a 40% chance you'd buy one and be happy or a 60% chance of being unhappy (CBU)
- If after you read the full forum, let's say your chance of buying one increases to 90% or a 10% change of being unhappy (CBU)
- Expected Opportunity Loss (EOL) = Bad or Good Outcome Value * Chance of Being Unhappy
Desire to buy SBM
before reading forum:
Buy SMB: EOL=BOV*CBU or $700*60%=
$420
Don't Buy:EOL=GOV*CBU or $3500*40%=
$1,400
Desire the buy SBM
after reading forum:
Buy SMB: EOL=BOV*CBU or $700*10%=
$70
Don't Buy:EOL=GOV*CBU or $3500*90%=
$3,150
The difference between the Expected Opportunity Loss is a representation of the value of the information contained within the thread. Essentially if you buy a SBM without reading the forum you are "paying" $420 for a 40% chance of being happy with your purchase. If you buy a SBM after reading the forum you are "paying" $70 for a 90% chance at being happy with your purchase. That's a difference of $350 or roughly $37 per hour of reading.
To make a long point short, if you are finding and reading this thread, you probably have more that a passing interest in the SBM. Make the investment to educate yourself and figure out if it is right for you. There is an obviously wealth of information here.
Don't ask the same question that has been answered many times over, you just waste time and thereby limit the available time for forum members to add to the overall knowledge base.