Dosing w/o testing

[Jeff Coart <rapdfire at pacbell_net>]

I could be accused of being penny wise and pound foolish - shopped
around for weeks till I found what I think are great prices on most
everything I needed to set up a relatively high tech plant tank. One
item I skimped on was test kits. In fact, I don't have an Fe test kit at
all and I'm pretty sure my NO3 kit reads way low.

My tank has been up for almost a year now. 50 gallon water column;
Heavily planted; 165W CF, 11 hour photo period; approx. 45 inch fish
load; Flourite; Dupla heating cables; PMDD fertilizer mixed and dosed
based on Sears/Conlin and occasional 1/3 Jobes spike for swords; DIY CO2
injection (yeast method - changed weekly to maintain around 15 - 20
mg/l); reverse osmosis water reconstituted with Kent R/O right and
sodium bicarbonate; KH: 4.5  PH: 6.5 to 6.9 or so; Eheim 2215 cannister
filter; 2 Aquaclear 201 powerheads for improved circulation; 20% weekly
water changes. I think that covers it.

As for dosing, I'm basically fumbling around in the dark. I judge how
much macro and micronutrients to add by how fast my plants grow and by
the level of algae present. During the first six to eight months of tank
operation I had a helluva time with BGA. At the time I was dosing
probably 2ml KNO3 daily in an attempt to get my NO3 to register on my
test kit which it never did. Traces were dosed at about 1ml every other
day. Subsequently, BGA was all over my swords and other plants. I
finally decided to cease fertilizer additions and reduce lighting until
I got the algae problem under control. In about two months or so most of
the BGA was gone and currently I have it under control. I am now dosing
about 1/2 ml NO3 and 1/4 ml trace every other day. K is added at about
1/2 ml daily. Plants are growing faster (I now have to trim certain
plants weekly) and the only persistent algae type in the tank is green
spot on tank walls and Anubius species. I am having problems with Rotala
Indica and Crypt Wendtii. Both plants develop clear patches on leaves -
Rotala continues to grow well while my crypt is melting. I read
somewhere that clear patches on leaves could be a sign of K deficiency
so as stated above I am adding K daily (for about a month now). I/m not
seeing any improvement in either species. 

I feel better about my dosing regimen since algae has decreased from its
high point by about 90% and plants are all doing pretty well with the
noted exceptions. Still, I read the posts on this list and it seems like
people are dosing much more than I do. I don't overfeed my fish (one
daily feeding - an amount they can consume in about 3 minutes). I know,
I know - buy reliable NO3 and Fe kits (I'm thinking LaMotte but they're
awfully expensive and money is tight).

Does my regimen sound reasonable or am I underdosing? Could my plants be
doing better? Are the problems with my Rotala and Crypt indicative of a
nutrient deficiency? Are test kits absolutely essential to achieve
optimum growing conditions for aquatic plants?

I'll shut up now; sorry for the long winded post. Any suggestions are
greatly appreciated.