No not really low, here is a chart to look at the ave on where things should be.
Alk/ dKH/ Calcium
0.00 0.00 360
0.50 1.40 370
1.00 2.80 380
1.50 4.20 390
2.00 5.60 400
2.50 7.00 410
3.00 8.40 420 (Near sea water)<
[hr]
you are right about in this
3.50 9.80 430 <
[hr]
range, not bad.
4.00 11.20 440< I personally prefer to be around here.
4.50 12.60 450
5.00 14.00 460
5.50 15.40 470
6.00 16.80 480
6.50 18.20 490
7.00 19.60 500