3a : to place or invest in such a manner as to make unavailable for other purposes their money was tied up in stocksb : to restrain from normal movement, operation, or progress traffic was tied up for miles. 4a : to keep busy was tied up in conference all dayb : to preempt the use of tied up the phone for an hour.
A 20-gallon tank is the minimum tank size for a reef or saltwater tank. Although it may be harder to maintain than a bigger tank, it is possible to create a saltwater tank using 20 gallons. Be mindful of the fish stocking to ensure that too many fish do not over-pollute the system.
A good filter, with no heater, is recommended because these fish can get larger than 12 inches (300 mm). Tank recommendations range up to 75 US gallons (280 l; 62 imp gal). It is possible to keep small goldfish in smaller tanks, but such an arrangement will be very difficult to maintain once the fish grows older.