Carmen Parr, as Parent and Natural Guardian of the Minor C.P.-P., Appellant, vs. Jerry Carl Immerman, et al., Respondents.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1996).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

 C4-98-960

In Re the Marriage of:

Kathleen Janasz, petitioner,

Appellant,

vs.

Joseph C. Janasz,

Respondent.

 Filed December 22, 1998

 Affirmed

 Amundson, Judge

Hennepin County District Court

File No. 1941116

Jody Ollyver DeSmidt, Walling & Berg, P.A., 121 South Eighth Street, Suite 1550, Minneapolis, MN 55402 (for appellant)

Lisa M. Elliott, Elliott Law Offices, 304 York Business Center, 3209 West 76th Street, Edina, MN 55435 (for respondent)

Considered and decided by Amundson, Presiding Judge, Foley, Judge,[*] and Thoreen, Judge.[**]

 U N P U B L I S H E D O P I N I O N

 AMUNDSON, Judge

Appellant challenges the administrative law judge's determination of respondent's share of child care costs for the parties' children, the determination that support above the guideline level is not required, the selection of the effective date for the modified child support, and the denial of her motion to compel discovery. Finding no abuse of discretion, we affirm.

 FACTS

Appellant Kathleen Janasz and respondent Joseph Janasz were married from 1985 until 1994. Appellant was awarded custody of their three children, who are now 10, 8, and 6. All the children attend a private school, and the oldest receives special tutoring there for learning disabilities. The children also participate in the school's extended day program (7-9 a.m. and 3:30-5:30 p.m.) at a cost of $130 per child per month for nine months ($3,510), and in a summer program at $550 per child per month for three months ($4,950). Appellant employs a nanny for the early morning hours at $312 per month.

Respondent's child support obligation was the guideline amount, $1,439.55 monthly; he was also ordered to contribute $389.70 per month for work-related child care costs. Both parties moved to amend child support. Prior to the hearing, they filled out "Obligee/Obligor Fact Sheet" forms. Appellant reported a net monthly income of $3,742.94 and respondent a net monthly income of $5,635 (the income limit currently in effect on the child support guidelines pursuant to Minn. Stat. § 518.551, subd. 5(k)(1996)).

In her original November 1997 motion, appellant argued that there had been a change in circumstances because the special needs of the oldest child had increased, justifying support above the guideline level. In February 1988, she amended her motion to assert an increase in respondent's income, justifying a new guideline amount. Respondent argued that the change in circumstances was a decrease in the cost of child care, justifying a reduction in his child care payment.

Following a hearing, the Administrative Law Judge (ALJ) raised respondent's child support to the guideline 35% of his $5,635 net monthly income, or $1,972.25, and reduced his child care to $211.50, retroactive to March 1, 1998. Appellant challenges the decrease in the child care payment, the denial of support above the guideline amount, the effective date of the order, and the denial of her motion to compel discovery.

 D E C I S I O N

Modification of child support is within the trial court's discretion and will not be reversed absent an abuse of discretion. Kuronen v. Kuronen, 499 N.W.2d 51, 53 (Minn. App. 1993), review denied (Minn. June 22, 1993).

 I. Child Care Payment

Appellant contends that the ALJ abused discretion in setting the amount of work-related child care costs. Pursuant to Minn. Stat. § 518.551(b) (1996), the ALJ set the cost of work related child care at $528.75 monthly, which is 75% of the amount paid to the children's school for the extended day and summer programs. Appellant challenges the ALJ's refusal to include the nanny's salary as a cost of work-related child care. Appellant testified that she needed a nanny for three school-age children already enrolled in an extended-day program

to help me out in the mornings so that the children don't have to get up at an extremely early hour so that I can get to work on time and they can get to school on time.

But she also testified that the children had to be in the extended day program because school did not start until 9:00 and "I have to be at work before 9:00 so they have to be there before that or I have to have a nanny * * *." The ALJ's finding that appellant's legitimate work-related child care costs did not include a nanny and an extended day program was not an abuse of discretion.

Appellant then challenges the proportion of the child care cost assigned to respondent. This also is governed by Minn. Stat. § 518.551(b).

The court * * * shall allocate the costs to each parent in proportion to each parent's net income, as determined under this subdivision, after the transfer of child support and spousal maintenance, unless the allocation would be substantially unfair to either parent. * * *

After the transfer of $1,972.25 in child support, respondent's $5,635 net monthly income becomes $3,662.75, which is 40% of the parties' combined net monthly incomes, $9,156.97. The ALJ ordered respondent to pay $211.50, or 40% of $528.75. This was not an abuse of discretion.[1]

Appellant objects to the ALJ's stated finding that her net monthly income is $5,507. This finding is an anomaly (or a misprint); it clearly was not used in the ALJ's calculations, and the ALJ's order regarding child care payments is adequately supported by information in the record. The finding is a harmless error, and we ignore it under Minn. R. Civ. P. 61. Where the findings necessary to a conclusion are adequately supported, a court's inclusion of other unsupported findings is harmless error. Petition of Santoro, 578 N.W.2d 36, 369, 378 (Minn. App. 1998) (citing Hanka v. Pogatchnik, 276 N.W.2d 633, 636 (Minn. 1979).

 II. Denial of an Upward Departure

Appellant argues that the special needs of the parties' oldest child justify an upward departure from the guidelines. The ALJ found that:

[The oldest child's] attention deficit appears to be under control with the benefit of Ritalin, and the child is currently not being tutored while attending the same private Montessori school as her two siblings.

While potential additional costs associated with [the oldest child's] future educational plan may justify a future deviation, [appellant] has not sufficiently demonstrated that [the oldest child's] present educational costs are substantially different from those of her siblings. Nor has [appellant] demonstrated that her current monthly expenses can not be met with her monthly net income combined with guideline child support.

The ALJ also noted that appellant's "total monthly living expenses are unknown" and that, although appellant had been advised she would need to submit information if she wanted the ALJ to consider her request for an upward departure, "[o]ther than child care expenses and her present mortgage payment, [appellant] provided no additional information."

Appellant argues that private school is necessary for the oldest child and that respondent should pay half the tuition, or $210 monthly, in addition to child support. Absent any evidence that appellant cannot meet her expenses with her present level of income and the increased child support; or that the expenses for the oldest child are greater than the expenses for the other two, there was no abuse of discretion in refusing to depart from the guidelines.[2]

 III. Effective Date of the Child Support Modification

Minn. Stat. § 518.64, subd. 2(c)(1996) provides that:

A modification of support or maintenance may be made retroactive only with respect to any period during which the petitioning party has pending a motion for modification but only from the date of service of notice of the motion on the responding party* * *.

Appellant argues that the ALJ abused discretion in making the modification effective as of March 1, 1998, instead of November 1, 1997. However, appellant's November 1, 1997, sought only above-guideline support; she did not petition for modification of the guideline amount until her amended motion, served and filed on February 13, 1998. The ALJ did not abuse discretion in setting increased guideline support retroactive to March 1, 1998.

 IV. Denial of the Motion to Compel Discovery

Appellant served discovery requests on respondent in November and December 1997 and served a motion to compel in January 1998. Respondent faxed replies to discovery on the morning of March 2, 1998, the date of the hearing. During the hearing, appellant did not mention either respondent's replies or her motion to compel, and the ALJ did not address any discovery issues then or in the order. This court cannot review what discovery issues the ALJ failed to address. "A reviewing court must generally consider only those issues that the record shows were presented and

considered by the trial court in deciding the matter before it." Thiele v. Stich, 425 N.W.2d 580, 582 (Minn. 1988) (citation omitted).[3]

We see no abuse of discretion in the amount of child support, the amount of work-related child care costs, or the effective date of the order, and we decline to address a discovery motion that was never argued before the ALJ.

  Affirmed.

[*] Retired judge of the Minnesota Court of Appeals, serving by appointment pursuant to Minn. Const. Art. VI, § 10.

[**] Retired judge of the district court, serving as judge of the Minnesota Court of Appeals by appointment pursuant to Minn. Const. Art. VI, § 10.

[1] Appellant reported her reported net monthly income as $3,742. The ALJ's calculations imply that her monthly income is $3,521.97, (60% of $9,156.97, the parties' combined income, less $1,972.25 in child support). This de minimis variation works to appellant's advantage, and we ignore it. Cf. Minn. R. Civ. P. 61 (harmless error to be ignored).

[2]In any event, appellant requested alternative relief, either support above the guideline level or raising guideline support to $1,972.25 monthly. Because the ALJ set support at $1,972.25 per month, he had no basis for granting both alternatives.

[3] We see no merit in appellant's contention that the ALJ could not accurately determine respondent's income without more information. Appellant moved to have respondent's support obligation be based on the maximum income recognized by the guidelines, and the ALJ granted that motion. Moreover, "[t]he guidelines in this subdivision are a rebuttable presumption and shall be used in all cases when establishing or modifying child support." Minn. Stat. § 518.551, subd. 5(i). Appellant does not rebut the presumption.