adjusting pmdd for tap nitrate of 30

[davideyre]

My tap water has nitrates of about 30ppm.

I am basing my dosing around James' PMDD page (http://theplantedtank.co.uk/PMDD.htm, thanks for the awesome site!).

Presumably if my plants use approximately all the nitrate added each day then I should add just as much nitrate as anyone else. In this scenario my nitrate level will just stay around 30ppm. Is this fair? James' guide mentions that with high starting nitrates you may be able to dose less. Just wonder what people's experiences have been?

Thanks.

 

[JamesC]

If you are sure that your tapwater contains that amount of nitrate then yes you may be able to dose less. If you are using a hobby grade test kit your results may be way out so knowing how much you actually have is very difficult. You may also find that your tap NO3 levels may flutuate during the year so you'd need to constantly check the levels. Most people don't bother doing this and just dose the recommended levels.

Do the normal dosing and once you are happy with everything then you can try cutting back a bit and noting any changes.

HTH
James