To my shame I decided not to go anymore with plants in my 10G tank. I left one fake plant and one Anubias nana (as this is considered to be the hardiest aquatic plant by many people and I still want to see what will happen to it), two pieces of aged wood. When I started this tank I had no knowledge about how and what should be done in a fish tank and now after getting all pieces of advice it turns out that it is not as easy as I thought to have plants - no proper lighting, need for different fertilizers, lack of CO2 system (preferably pressurised), etc. So instead of rushing things I made up my mind to stick now just to the fish and get the necessary experience for the future when I will feel I am ready both with my knowledge and finances to start a planted tank. Though I could say one thing I started saving for a bigger tank and maybe with this one I will try to do some planting (following the principle: ask here first, then do it in your tank).

I am really sorry for being such a noob with all my mistakes I have done before.

Kara is becoming something special to us, I purchased it from a shop which kept it as a feeder fish and it turned out to be a very nice Comet lady. I think I saved it from death (being eaten by a piranha or someone else...)
I apologize for being a nuisance - you folks put into us, noobs, so much effort that is why I felt sorry for not being able to cope with them.
Due to some room restrictions I am thinking of another tank in the range of 30-40G. Do you think it would be a good choice taking into consideration my ignorance?

Actually yes I knew this, one needs a longer tank with more surface than a shorter one with less water surface as the level of oxygen in the water depends on this. Am I right?
As for the Comets I would like to buy a pair to my Kara so it would not be so boring for her to sit in my tanks. And taking into consideration that a Comet needs 15G per fish it would be ideally to find a long 40G tank to have there 2 Comets and "smaller" goldie. Plus the old 10G Tank could be used as a quarantine tank and a hospital. Or a betta tank. It depends as no one knows what the future brings to us.

Max, Minde already covered the tank issues, and I agree as well with the following:
Please, please don't apologize, you are OK and we all started on here as "noobs" but we all INCLUDING YOU are willing to learn about this wonderful hobby.
And we all enjoy helping people like you.

Now to the plant issue: You really don't need a CO2 system, they are very expensive , as you know.
I have quite a few plants in our tanks, the only thing i use sometimes is "Flourish" or similar plant fertilizers, nothing else.
OK, from time to time some plants need to be replaced, as the fish nibble it away.
Algae? well they are a sign of a healthy tank, but look ugly. To keep their growth under control I use "Algae Control" ( plenty other products around for this purpose too )

Have a look around in the pet stores, you sure will find what you need, and those products are not expensive.
They also may sell certain plants where you can chose 4 different ones for one low price.

And here are the reasons why I recommend plants:
1. lovely snack for Lady Kara
2. during daytime they produce O2 and consume CO2 (night time invers >>> see photosynthesis)
3. plants also consume nitrates (>>> see Nitrogen cycle)

But whichever way you go:  Can we see some PICS, please ? 

And BTW; Lady Kara is very lucky to have such a good Fishdad

I am as well.

I've got the algae scraper too, but I use the algae controll to minimize the growth of them, lol, easier than scraping them off

Can I just say one thing?
Yes algae is unslightly but goldfish actually thrive on it and it does help keep nitrates in check!

Correct Minde, algae control is not meant to eliminate them, but to keep it under control, ROFL

Max, please check your PM, 

I don't even know who Jack is!

Thank you for the link, will have a look now. That is quite an impressive commentary, I really appreciate this.
As the dimensions - not really sure but our furnished apartment would not fit something bigger than a 50-55G tank and still this should be considered as my wife has some plans as well for the spare space available in the rooms. She wants a wardrobe so we need to negotiate.
The algae on the walls does not bother me. What I have experienced in the past is the green water and that what I do not want to have it back. Had to work hard to get rid of it.
As for the algae on the plants not all algae could be easily removed from the leaves. Like I said in my other forum threads bba I had on Java Ferns was practically impossible to remove with a sponge. Although I managed somehow to significantly diminish the amount of it on the leaves with Flourish Excel.
And it would be a good idea to try again a planted tank with my current one as soon as I get another one bigger.

LOL, Jack is HIJACK ( hijacked thread, lol )

whoops I just did again!!!
Hello, my name is Jack, I just hijacked this thread! LOL!

Oh I get it hiJACKed!

Omg! you sound like a school marm!!!! ROFLMAO!!!!!!!