If the plants are browning and losing leaves and stems in the water then it'll raise it.
Algae reduction growth might be worsening it as well. Will consume nitrate when actively growing.
Doubt it's the lfs substrate unless it's deep and lots of detritus and stuff is in there and got loose.
Atleast in the short run try a little purigen in a high flow area. I know jaws7777 did this in his tank and it really helped. This will need to be cleaned but will help along with water changes.
substrate is about 1.5-2 inch thick. Sometimes more in places. The del consistently digs and moves things around. Not sure if this is enough to prevent a nitrite-> nitrate spike
I'm also seeing more of the strands blackbeard algae or the feathered algae) which of course is freaking me out.
Short term fix: for the purigen, can I just stick it in my filter? It's the AC110. Ironically I was looking at Frank's purigen/nitrate filter build a few days ago, but then got discouraged because I don't have a sump and that's the only time I've seen purigen used. Still learning about the concepts of cycling and beneficial bacteria.
As far as filter cleaning: this might be the culprit? how often should I change it?
- I have the traditional set up for the AC110. The cermaic media was new in April 2017(so it is 7 months old). I did replace the carbon two weeks ago. Remember reading that carbon isn't necessary though unless if I'm taking out medication. I clean out the sponge media every 1-2 weeks. Though the sponge gets filthy. Haven't changed the sponge since April. I also have polyfil if that would be helpful. Maybe I'm not taking proper care of the filter or am changing the media enough? I don't have any experience with cermic media.
For the plants: would it be beneficial to add more plants or would this make the problem worse?
Fish appearance: would high nitrate cause white patches to form on one of the poly's faces? it kinda looks like ich, but it is flat and seems almost like white scales. The spot is on on parts of the face by the eyes and then a few spots on the "meaty" part of the pec fin. Not sure if it is the sensory pores or if this is related? Can get a pic.
sorry for the long post. Thank you everyone for your help and patience.