Question
hello again,thanks for the answers to the filter questions i had.My next concern is,. instaed of putting plants in a pot, can i put a couple inches of play sand then gravel in the bottum of the pond and let roots grow there? And one other thing,....My temperture of my pund has stabalized now at no lower than 50 degress at night and 62..68.. durring the day time,,,is it safe at this point to add the goldfish-----------------------
Followup To
Question -
hi,i just finished my pond and added water, it came with a 600 gal pump, with fountain and water fall. One of my questons, are will i need a filter with it,or will the pump keep it clean? My secound question is at what temp can i add some goldfish?
Answer -
If I read this right you have a 90 gal. pond with a 600 GPH pump. If this is true a simple inlet filter on the pump should be OK and by all means have goldfish. What I would suggest is get some feeder fish from the pet store. They are about 35 cents each I would think about 6. They are smal and grow fast. This way if you have problems  cheap fish are better to lose than expensive ones. Don't forget some real plants in the pond what you are building is a mini eco system. Your entire pond should recycle about 6 times an hour which should be great.

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         Leigh

Answer
Both answers are no problem. The roots will do their thing in the sand and the fish will do quiite well. The only thing you might watch is feed the fish miday. The reason I say that is if the temperature get much under 50 degrees. The fish metabolism starts to shut down and if you feed them too much they can poison themselves. Hence the cheap fish until to learn by experience.

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         Leigh.

Keep the questions coming if you are not sure