What size tank do I need for the following fish?

25 is the bare minimum for the tetra's (need groups of 6) and the platties (need groups of 3) The siamese Algae eater needs 30-40 gallons as they reach 5.5 inches and get agressive often sucking the slime coat off of other fish as they get older. A better choice would be to get a 30 gallon and ONE bristlenosed Pleco. They're good algae eaters and you would need the extra five gallons to house the pleco in. 25 for the tetra's and platties and 30 if you want the Bristlenosed Pleco.