Need help ASAP! Arcylic and sealer problem

[nevertoomany]

I have been re-building my 75 gallon with a false bottom, GS background. I then covered the GS in pottery plaster, then painted with acrylic paint. To seal the paint I used Modge Podge. After it dried for 48 hours I added the plants and sprayed the whole cage with water.(for the plants and substrate) After I did that, everywhere that I coated in modge podge turned white! It looked just like it did when I applied it. What is wrong/what did I do wrong? The background has a waterfall and a river that is coated as well. Please help if you can.

Thank you in advance for all help,
Justin

[nevertoomany]

After looking at more builds on here, modge podge is only good for dry tanks. My fault for for assuming it would work in tropical set-ups as well. Guess its time to start over...