Yes I did test the ammonia as well! Both ammonia and nitrite levels were at 0. Nitrate was about 20; the instruction booklet said that anything up to 30-40 should be alright. Is a higher level actually recommended, or it the lower the better?
And yes I made for sure leave the other filter in while adding the new one! I did some research on it beforehand to make sure that I did it right and the site I read suggested the same as you. Would you say it is best to keep them both going or to remove the old one eventually? I can easily keep it running if that is better then removing it after the 3-4 weeks.
I have a question about picasimus fish, by the way. The lady at the pet shop told me that they help to keep tanks clean and she'd recommend having one in every fish tank with an already established community of fish. Is this true? If so, do picasimus get on well with goldfish, generally?
If you have anymore suggestions or tips for me, please share them. I'd like to keep my fish living healthy for as long as possible. I'm very grateful for everything you've told me!!
Both ammonia and nitrite levels were at 0. Nitrate was about 20; the instruction booklet said that anything up to 30-40 should be alright. Is a higher level actually recommended, or it the lower the better? 
