Hi Darkmoore and Jacques

!
Sorry to hear about your fantail!

It is very sad but that tank size cannot hold 2 goldfish and keep them healthy. Many of us started out the same way - at least you have a filter and an airstone! - so there are no hard feelings, it is just the sad truth that the petstores often do not educate people about the best environment for fish...
I have a blackmoor - an orange blackmoor (he decided to change colors to express his joy) - I had him in a 3 gallon tank for a several months with 2 frogs and an oto cat - until he got sick! That's when I found Koko's. I learned a lot! I thought I had been taking good care of him - and I was to some degree - but applying what I learned here has made him a really happy healthy huge fish!
It is true that the recommendation for a fancy GF is 10 gallons per fish - I find I can endorse that now that I have seen it in action! It has changed my fish's life! THere are lots of ways to try to "upgrade" - I know it can be quite a shock to find all this out - I am still recovering myself!
If you would like to get another fish - then maybe you can move straight into a 20 gallon... I find lots of stuff at www.craigslist.org which is local and you can inspect stuff before you buy it - lot sof fishtanks available! But, I would not keep more than 2 GF in there. Just make sure you have enough filtration and that you do regular water changes. You might even see Jacques grow! Also, if you don' t have a cat, you could use a Rubbermaid tub for a awhile or even permanently if you like the indoor pond look!
Blackmoors are truly adorable sweet loving fish! I hope Jacques gets a buddy - and maybe a bigger tank for both of them!

PS - In the tank J. is in now, I would do 100% water changes every day to every other day. In a bigger tank (min. 10g) I would do it maybe 30% once a week - mor eif the water quality dictated it. I have a 20g with one fish and a huge filter - and I do 25-40% water cahnges once a week - amount depends on the nitrate readings. When I was cycling, I did the changes more frequently to help keep ammonia and nitrite levels from harming my fish.
Don't forget water conditioner! A very good one is Prime and it is not too expensive.
One small piece of advice - I did it the expensive way - go for the biggest tank you can handle, otherwise you will start accumulating tanks like I did! I moved my fish from 3 to 10 to 12 to 20 - now I have lots of tanks and I spent a lot of money that could have gone straight into the 20!
Please feel welcome to come. make long posts (

) , ask as many questions as you like, and post some pictures!