has anyone ever tested MDMA, it turned black, but it was very weak?

[edubz]

Does a strong reaction to the tests always mean a powerful product?

 

[BlueBull]

Yep, numerous times, a strong reaction isn't a good indication of purity. Testkits are pretty sensitive so even a small amount of MDxx in the sample will make it turn dark purple/black. And sadly this colour overpowers other colours, which makes spotting adulterants even harder. A good idea is to buy a full testkit (marquis, mandelin, mecke, simons & robadope) and test with every reagent. This will increase your chances of spotting adulterants because you have 5 tests on which to look for irregularities. Also some reagents (robadope) do not react to MDMA but they do react to PMA or PMMA, which is a help when you're dealing with a mixed sample (MDMA+PMMA for instance). See here for a chart with all the reaction colours. As you can see the combination of colours on 5 testkits tells you much much more about the sample than 1 single colour on 1 test will