I added some fish yesterday to my two tanks. And some plants today. My little Oto kept coming up to the front sucking on the glass and I could see red, I guess it's around his gills so I tested the water I had a spike. .25 ammonia and up on my Nitrites. I usually do my water changes on Sunday but we did them today. I used my Aqueon water changer DIY. I had already bought one on eBay for about $25 but it wouldn't fit my faucet. Bought another one on eBay and it wouldn't fit either. Those were the two major named water changers. Then I found this one just the attachment that goes to the sink at Petsmart for $10. Got two 10 ft half-inch tubing at Home Depot for two dollars each with a connector. Total around $14. I live in an apartment and do not have access to a hose. So water changes are now a breeze. I'm sure most of you already have one but for the new people definitely get one. I will test my water tomorrow and see how everybody is. Do plants change water parameters?