20 minutes wouldn't have done much damage at all......I think the Amquel could have affected the results.
Your tank is still new (2.5 months setup) and diatom algae is common in new setups. Scrub what you can off the decor and eventually it will go away on its own.
How long do you leave the tank lights on in a day?
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*Kristin*
5 Planted tanks:
55g, 40g, 29g, 10g, 5.5g
10g N. multifasciatus tank, 5.5g Platy fry
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