Chasing my own tail?

[AndrewK]

I recently (2 weeks) purchased a 20g, added a HOB that was in use on a 10g, a heater, and a sponge filter that was also in the 10g. I have 1 killifish, 3 guppies, and 3 dwarf gouramis.

In my 75g that I've had for years but recently planted, my pleco decided he didn't like real plants and uproots them every chance he gets. I have since moved most of my plants to the 20g.

I took the fluval 2.0 off of the 10g and put it on 20g.

Chemicals: seachem prime, flourish, and API quick start. 

Question : using the flourish, am I adding a bunch of nitrites? 

Follow up question: using the API quick start, am I negating the flourish?

And finally: are these brown spots algae or a deficiency?

 

Nitrate : 50

Nitrite : 1

hardness : 300

KH : 120

PH : 7.4

Chlorine : 0

amonia : 0

This is after a water change of 25%, with prime and quick start.

[Mmiller2001]

Flourish dose not add nitrite and is not a significant source of NO3. Also you are not negating anything by dosing both.

Brown spot are probably diatoms. If they turn black and you see tissue necrosis, then you should address your fertilization.

[Kirsten]

API Quick Start is just nitrifying bacteria to help process fish waste faster. It should have no effect on your plants other than slightly positive, since plants will consume all parts of the nitrogen cycle, but like nitrates most. If anything, it'll help consume ammonia to turn it into nitrites, and consume nitrites and turn them into nitrates.

Flourish, from what I understand, is a fertilizer and it's completely different, but it might help feed the colony of beneficial bacteria.

The pics you posted look like normal brown algae to me, totally common in new aquariums. Reduce light to 8 hrs/day, feed lightly and try easy carbon or algae eaters like shrimp to help it die back.

Your water sprite looks a bit like mine.

I've tried 3-4 times to get it to take, but no dice. It can be pretty finicky. For what, I don't know yet. But luckily there are other plants that grow great for me like jungle val, chain swords, anacharis, camboba, and most epiphytes.

Sometimes you just have to try a bunch of different things and see what sticks.