Problem using both NovAqua+ and AmQuel+?

Amquel+ and Novaqua+ need to be used in conjunction to condition the water properly. If you want something that is a bit more concentrated and only requires one bottle to do the same job, get Seachem Prime.

Some things need to be considered before making a choice, Amquel converts ammonia into a safer compound that won't hurt fish but leaves it available for the biofilter and plants to consume, it converts it for good. Prime only locks the ammonia etc for about 48hrs then slowly releases it to the biofilter. So, in short, Prime is great for cycled tanks, but Amquel+ and Novaqua should be used in small uncycled betta tanks that require 100% water changes every other day to keep ammonia from building up. The permanent nature of Amquel+ will help provide a safe guard against the slow buildup of toxins in a beta bowl until water change day, Prime will do nothing to assist this and since there is no biofilter present in an uncycled bowl, Prime only releases the toxins to do harm to the fish.

Something very important to know, liquid Amquel+ will crash PH if your KH is too low. In this case you need to switch to Prime for a cycled tank, or dry powdered Amquel+ with added buffer for an uncycled tank. The added buffer of powdered Amquel+ counteracts it's pH lowering properties. When emergency double doses are required to keep toxins at safer levels while the tank cycles or the biofilter falters after cleaning, I recommend Prime because of amquel's effect on pH and Oxygen levels. I have had very negative results with Amquel plus overdoses but none with Prime.

I personally like to have both options in the house for different situations.

I have not heard of any shrimp problems with either, but Amquel plus can moderately lower O2 concentration for the first few hours after use, so that may have been the issue with others and their shrimp.