Okay, again with the goldfish

I've had goldfish In my 30 gal. tank for 5 weeks now. It has a filter, and I put de-chlorine drops In the water. I clean the grave and do water changes once a week. The only thing I don't have Is a heater(bad for the goldfish), I was wondering If my tank has been 'cycled' and Is ready for tropical fish once I find my goldfish a new home. And what exactly Is 'cycling'? Does It mean all the water has gone through the filter and has been treated with de-chlorine drops? I seen talk about algae, does there need to be algae In the tank for the new fish? I honestly don't see ANY algae anywhere In the tank. I'm a beginner, so I'm sorry If I'm asking too many questions. But I so appreciate your opinions. Thanks!!

Yodi

 

Your tank likely has cycled. (but this is not guaranteed. Mine took months to cycle)
https://www.fishlore.com/NitrogenCycle.htm
Here is a good explanation of the cycle we're talking about. In short, it's the growth of the bacteria that eat ammonia and produce nitrites, then the growth of the bacteria that eat nitrites and produce nitrates (which are much less toxic to fish than ammonia or nitrites).
Algae is not necessary. In fact, it can be harmful to fish if there is too much of it. I'm keeping something that eats algae in each of my tanks to keep the population down.

Also, when you find a new home for your goldfish, you can make their transition, and the cycle of their tank, easier by transferring part of the first aquarium's filter to the goldfish's tank filter. (Just taking a little bit of the carbon out of the filter bag, if you're using the kind that rests on the back of the tank, and putting it in the new filter's bag will seed the bacteria, giving them a jump start on growth, if that makes sense.)

 

The only thing I don't have Is a heater(bad for the goldfish), I was wondering If my tank has been 'cycled' and Is ready for tropical fish once I find my goldfish a new home.
Yodi

You don't need a heater for a goldfish since they're coldwater fish, but it's a good idea to have 1 for an emergency. Also, tropical fishes and goldfishes usually don't mix very well.

 

The only thing I don't have Is a heater(bad for the goldfish), I was wondering If my tank has been 'cycled' and Is ready for tropical fish once I find my goldfish a new home.
Yodi

You don't need a heater for a goldfish since they're coldwater fish, but it's a good idea to have 1 for an emergency. Also, tropical fishes and goldfishes usually don't mix very well.

I think what YodI is saying is that, once a home can be found for the goldfish, the tank will be ready for the tropicals that will be going in it. The goldfish was just being used to cycle it.

 

Actually I have a heater in my goldfish tank so that the temperature can be kept constant

 

The only thing I don't have Is a heater(bad for the goldfish), I was wondering If my tank has been 'cycled' and Is ready for tropical fish once I find my goldfish a new home.
Yodi

You don't need a heater for a goldfish since they're coldwater fish, but it's a good idea to have 1 for an emergency. Also, tropical fishes and goldfishes usually don't mix very well.

I think what YodI is saying is that, once a home can be found for the goldfish, the tank will be ready for the tropicals that will be going in it. The goldfish was just being used to cycle it.

Oh...sorry! ;D

 

Actually I have a heater in my goldfish tank so that the temperature can be kept constant

You really don't need to. They can be kept in the ponds in winter and hibernate. It's actually good to let the temperature drop once a while. Goldfishes store fat and the cold temperature makes them hibernate which makes them lose fat.