204 GOLDFISH VARIETIES AND 
It is very nice to sink a hole in the centre for the reception of a 
water lily plant. This adds considerably to the planning and labor, but 
the result is worth it in satisfaction if one is fond of beautiful aquatics. 
At the same time the bottom can be drained towards the centre, a good 
point when it comes to the annual cleaning-out. Figure 163 shows this. 
The hole ought to be about 18 inches wide at the top, 15 at the bottom 
and 17 deep. The galvanized iron form is removed by bending it inwards 
at one point. This form is of thin metal and has no bottom, it being 
impossible to withdraw a bucket on account of suction. 
Another added attraction for those caring for the aesthetic side is 
the addition of tiles in the edges. To try to push these into the finishing 
coat is to court certain trouble and a botch job. As soon as the concrete 
is poured the tiles should be set on little mounds of cement as indicated 
in Figure 164, seeing that they come to exactly the right level, fixing the 
four corner ones first. Next day the finishing coat is filled around them 
and they help to establish the correct level. The cement will slop over 
on them a little, but this is no matter. Most of it can be wiped off with 
water and the balance after drying, with dilute hydrochloric acid. 
The author is not partial to drain-pipes. They may become dislodged 
and let the tank run dry, or, on the other hand, they may get sand in them 
and not go back into place. However, this is a matter of personal pref- 
erence. 
In two days after the finishing coat is applied, a little water may be 
run in. On the fourth day fill completely. All cement containers should 
be seasoned before the fishes are introduced. 
This can be done by changing the water six times over a period of 
two weeks. This is not thorough and a longer time is better. Seasoning 
can be accelerated by different chemical processes. The safest is to fill 
the pool and slake a large piece of lime in it. In a pool 8 x 12 feet, slake 
about half a bushel. There is no danger of using too much. After slak- 
ing, stir every few hours and clean out thoroughly in two days. Another 
method is to place a piece of blue litmus paper (obtainable in drug store) 
in the water after it has stood a day and been stirred up. Then slowly 
add and stir in commercial sulphuric acid until the paper shows a faint 
pink hue. Allow to stand another day and if the paper goes back to blue, 
repeat addition of acid. When the pink shade remains draw off water, 
clean thoroughly and use. Enough acid to turn the paper a distinct pink 
or red should not be used. Always stir water well before determining 
color of paper. This test is only for the acid process. 
Aquarium or Tank Capacity. To ascertain the gallon capacity of 
any rectangular tank, multiply the length, breadth and depth together in 
inches. Divide by 231. The result will be in gallons. 
A gallon weighs 8 1-3 pounds. 
