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.
For gas water heaters with storage tanks 30 to 50 gallons in size, for example, the increase in the minimum standards will trigger an increase in the insulation needed, resulting in a larger tank diameter. This can be as much as 2 inches or more in some cases.