Nutri-Calc & MgSO4

Nutri-Calc indicates 3 1/8 tsp MgSO4 3 times a week for my 77 (UK) gall tank which seems quite a lot - I'm sure it would have a devastating effect on me
I have dosed it at this rate for the last week and the plants have definately improved in growth and appearance, however I have also noted that new leaves on my HYGROPHILA are very curved-in on the sides - is it likely that the MgSO4 dosing is causing this.
All the other plants seem fine.

The other point I've noted is that cabomba has taken-off like crazy since switching to EI. I have to trim about 6" from each plant every day, mainly because the internode distance is now about 6"

I've been a convert to Tom's EI dosing since 1/8/06
100 UK gall tank - approx 77 galls H2O
3 x 36w triton tubes - 12 hrs/day
2 x 150w metal halide lamps - 9hrs/day
Eheim 2329 wet/dry (bio) filter
Eheim 2217
Pressurised CO2 when the MH lamps are on (around 10 bubbles/sec (?)too fast to tell really)
pH of outgassed tank water ~7.6
pH before CO2 switches on ~7.1
pH at lights out ~6.4
(pH values from pH controller)

Thanks
Pete
CO2 photo diary at - http://uk.pg.photos.yahoo.com/ph/speedy99uk/my_photos

 

Re: Nutri-Calc & MgSO4

Thanks Quenton

You say that you use 1/2 tsp to bring your Mg level up in 77 galls, yet NutriCalc indicates a little over 3tsp 3x per week for my tank.

As you suggest, it seems I have VERY little CO2 in my tap water, in fact it seems I have a negative amount of MgSO4!

Mg testing
((17.86 x dGH) - (2.5 x Ca ppm)) / 4.1 = Mg ppm

Using this formula I get the following -

((17.86 x 13) - (2.5 x 95)) / 4.1 =
(232 - 237.5) / 4.1 = -1.34

Hmmm - so I have -1.34 ppm Mg/l

The dGH and Ca ppm were derived from the Nutrafin test kits and these results have been stable over several weeks.

Here's the word for word instructions from the Nutrafin tests for Ca -
(NB - I used 5 drops of reagent 3)

CALCIUM ANALYSIS VERSUS GENERAL HARDNESS ANALYSIS

Ca2+ mg/L (ppm)
Multiply the total number of drops of reagent #3 used by 20 to determine the Calcium concentration.
To determine the ratio between Calcium & Magnesium
1. Calcium mg/L (Ca2+) (multiply by) x2.5 = Calcium Hardness mg/L (CaCO3)
2. General Hardness mg/L (CaCO3) (minus) - Calcium Hardness mg/L (CaCO3) = Magnesium Hardness (CaCO3)
3. Magnesium Hardness (CaCO3) (divided by) / 4.1 = Magnesium mg/L Mg2+

Thanks
Pete