I understand. But your showing ammonia which points to a mini cycle. And your nitrates are more then double what most like to see after a WC. The 50% WC every day for the next three days will lower your nitrates. And keep your ammonia down while your filters cycle. Also you could jack your temp to 81-82 and dose some salt. It helps with healing and can't hurt.
My gut is pointing toward a mini cycle and your ammonia and nitrate reads just are t where they should be. After a WC I like to see 0 Ammonia, 0 Nitrite, 10-20 Nitrate. I do a 50-60% WC weekly. Gravel vac weekly. And change the filter socks on my filter socks on my sump daily. Your filter set up doesn't allow you to clear you mechanical filter daily. When is the last time you broke into your FX5? I clean my FX5 every 3-4 months. But again the water my FX5 gets is prefiltered with a filter sock.
Mike
My gut is pointing toward a mini cycle and your ammonia and nitrate reads just are t where they should be. After a WC I like to see 0 Ammonia, 0 Nitrite, 10-20 Nitrate. I do a 50-60% WC weekly. Gravel vac weekly. And change the filter socks on my filter socks on my sump daily. Your filter set up doesn't allow you to clear you mechanical filter daily. When is the last time you broke into your FX5? I clean my FX5 every 3-4 months. But again the water my FX5 gets is prefiltered with a filter sock.
Mike
how often are your WC? Maybe do 40% 2x weekly until you've got the nitrates under control? Also maybe fill one of your Fx5 baskets with Seachem Denitrate? It looks like Matrix. 
