I look in vain for such a requirement in 1 Timothy 3:1-7. The text does say that the elder should be able to run his own household. Presumably that would include the ability to judge for his own family's well-being which school to send his children to. If the elder can't be trusted to make that decision, then he probably fails the biblical standard, "If anyone does not know how to manage his own family, how can he take care of God's church?" Here's what Lester DeKoster and Gerard Berghoef advise in The Elders Handbook:

I read this and thought about our current list of elders and couldn't think of one that is currently sending his children to Christian school. As far as I know, it's not a requirement to be an elder or even a pastor (yes, we had a pastor that sent his children to public school as well). The Christian education debate is a delicate issue not only if your church is gaining members without a CRC background (like myself) but also if your church is in a non-CRC area, so Christians schools tend to be Catholic or otherwise not following in the outline laid out in this recent and well-written Banner article. That is where our current congregation stands. They did try to have their own school for a while but they couldn't keep it going. Where do I stand? We prayerfully sought direction from God, and He confirmed what we always felt -- that we are called to be beacons of light in our neighborhood, and our neighborhood is centered around the public elementary school. So our daughter went to kindergarten in the public school. We couldn't have prayed for a better teacher than the one she had, as well as a better administration. The road may not be easy, but we know this is what God wants for us now. And how does our church answer the pre-classical censure question? When I was on council last (5 years ago) we answered that we did not do a very good job supporting Christian education. As far as I know, nothing has ever come from it.

The Church Order's latest version of Article 71 concerning Christian Education was fashioned after a thorough synodical study of the matter and reads as follows: "The council shall diligently encourage the members of the congregation to establish and maintain good Christian schools in which the biblical, Reformed vision of Christ's lordship over all creation is clearly taught. The council shall also urge parents to have their children educated in harmony with this vision according to the demands of the covenant." So, elders must encourage establishment and maintenance of "good Christian schools." Elders do that in view of their own context. Sometimes it is simply not feasible, financially. Sometimes it is not necessary (I think of the public school in one town that was explicitly Christian and Reformed without anyone objecting). When no Christian education is available and establishment is impossible, the church should "amp up" its Church Education program so that this can supplement the public education being received. In any case, it is clear that the elders together in consistory make a judgment call as to how in their own context this "encouragement to establish and maintain" plays out. If good Christian schools are available, I do not doubt that the Church Order and synod basically asks elders to urge parents to have their children educated there and I understand people who say that the elders' urging is meaningless if they do not model what they urge. What should be observed, however, is that eligibility for the office of elder is a judgment call on the part of every council. Article 3 of the Church Order indicates only that the person must be an adult confessing member and meet the "biblical requirements" for office. As we all know, such a requirement is not explicit in Scripture in the context of eligibility for office. Councils may wish to appeal to the "ruling your household well" and especially to the eminently clearer direction in our baptismal theology, Church Order and denominational ethos (including past studies and conclusions). But then they must also go on to decide in their own context on whether a person who does not send children to a good Christian school but, for example, to a public school, is nonetheless eligible to serve as an elder. I recall a situation in my own ministry career where an elder did that purely and entirely because services for his special needs child were not available in the Christian school system and where he and his wife as well as the church were "supplementing" what was happening in the public school in question. We made the judgment that the man was behind the principle of the CRCNA but had a legitimate "exemption" from the "requirement." A synodical study recently pointed out that home schooling is also a legitimate option. That would be an example of another "exemption." My point is that these judgments are never simple. If they are made to be simple, they are usually legalistic in character. An example of that is a recent decision of the Protestant Reformed synod that one who homeschools his children and does not send them to the Protestant Reformed school (only that one, not a CRC-related "good Christian school," because it doesn't meet the standard, presumably) may not serve in the office of minister of the Word. My plea is twofold: one, that we respect the right of local councils to make judgments about eligibility for office and, two, that we respect the denomination's stance on Christian education as much as we possibly can.

I have struggled with this whole Christian Day school issue since my kids were small. They've attended about half and half of their school careers. Without getting too deep into it, I see inherent problems with the current state of most Christian school philosophies especially when it comes to the mission of the church to the world around it. I have watched parents abdicate their responsibilities to Deut 6:6-9 and leave it up to the school to educate. I've seen many schools try to play the role of the church by using church curriculum. And there is an issue at hand of parents having to scrape every dime together to pay for Christian ed at the detriment of tithing to the ministry of the church which is first and foremost. I do not believe that sending your children to Christian school should be a requirement for serving in office. Anyone who says so is reading much more into "ruling your household well" than Paul ever intended.

I question the right of  councils to make a these type of decisions. Evalualting anothers faith is a very difficult.