You will need: (2240/625)*250=896 ml of treatment liquid. If each bottle contains 250 ml you'll need 3.6 bottles (3 bottles and a bit more than half a bottle).
I do not think you need the conversion 1 cubic meter=1000 litres unless the volume of the tank is in cubic meters BUT 2240 cubic meters seems too large!
Consonant blends (also called consonant clusters) are groups of two or three consonants in words that makes a distinct consonant sound, such as "bl" or "spl." Consonant digraphs include bl, br, ch, ck, cl, cr, dr, fl, fr, gh, gl, gr, ng, ph, pl, pr, qu, sc, sh, sk, sl, sm, sn, sp, st, sw, th, tr, tw, wh, wr.
