The only thing fighting for pH are the buffers in your tap water (and mine). I have found that peat-filtered water's pH levels remain lower much longer than any chemicals (pH down) I used to use. You don't want to be chasing pH up and down, it will do a number on whatever fish you have in your tank and, unless you have the time to document everything and perform repeated testing, you'll never end up with the same results twice.
When I first tried filtering tap water through peat, I tried several different set-ups - indoors and out, and what worked best for me on a small scale was:
1) A plastic bucket with several 1/4" holes drilled in the bottom for drainage, about 3" of quilt batting (Michael's, Walmart, or any sewing shop), and sphagnum (aka peat) moss;
2) A larger (in diameter) bucket to catch the water underneath the hole-drilled bucket;
3) Wood boards (a couple of 2" X 2" X 18") to support the drilled bucket;
4) Several empty 1-gallon Arrowhead drinking or distilled water bottles - for pouring tap water into the drilled peat bucket and a for storing extra peat-filtered water to top-off tanks.
That's all you need unless you have a gazillion tanks like I do now LOL. The 8.0 - 8.3 tap water I filter comes out at less than 6.0 pH with new peat moss. That number will slowly climb the more you filter water through it, but it would last a long time if you only have a tank or two...6 months to a year maybe at less than 7.0 pH.
If you did water changes of say, 20% once a week and replaced the tap with peat water - testing along the way - that would probably be a good recipe to bring your pH down to a desired level and simply topping the tank off occasionally with peat water will keep it down.
If you want to give it a try, holler back because there are a couple of other steps/tricks you need to do.
Regarding the rams - you can try a 1M / 2F ratio, but if any one of them doesn't like any one of them, you will know it within a few days if they play well with others or not. They may be nippy and chase one or each other for the first couple of days until a pecking order is established, but if that continues you'll need to separate either the one who is being picked on or, the one who is picking on the other two.
Females tend to get along together, but less often so if there is a male to fight over. If you have two females or one male and one female, that would be your best bet. Even if a male and female do spawn and you don't want to raise the fry, if the parents don't eat the eggs or fry themselves - if the eggs even make it long enough to be fry, the barbs will eat them. It wouldn't be as though you will be required to intervene - that's what happens in nature (easy to say but I'm a sap when it comes to saving fish too ; ). If nothing else, it is really interesting to watch the rams' behavior and spawning techniques.
Good luck!
