Plants lacking in what?

[Bertie]

Thanks Ian...I have a 180 litre tank also but will try not to copy you!! Just a quickie though....when the plants start getting the "right" fert will the gsa already on the leaves die off or do I need to cut off the affected leaves,as I think on some of the plants they would be pretty bare afterward.

 

[dw1305]

Hi all,

Also I have very hard water in this location(Hertfordshire)..would I need any Mg?

You will need to add magnesium, like "davem" says, all the general hardness is as Ca++ ions from the chalk aquifers over most of the S. UK.

Calcium ions can also block the uptake of both Mg++ ions and K+ ions if the calcium:magnesium and calcium: potassium ratios are high enough. You also get precipitation of iron hydroxides and calcium phosphate in really hard water, taking both PO4--- and Fe++ ions out of solution.

A short term fix would be to add some potassium nitrate (KNO3) and "Epsom Salts" (MgSO4.7H2O), these should give a fairly rapid greening response. If we ignore carbon (which plants require in the largest amount as the basic building block of photosynthesis) most deficiencies are either N or K. Although we usually talk about the 3 macro elements (as N: P: K), plants need about x10 as much N and K when compared to P.

Magnesium is the micro-element that plants require most of, although this is in small amounts even compared to P, but yellowing and chlorosis are frequently caused by low levels of magnesium in the plant. The central atom of the chlorophyll molecule is a magnesium atom, which is why you get yellowing when it is deficient.

Chlorophyll is a pigment, but it is bound to proteins in a "photosynthetic reaction centre". If you don't have sufficient nitrogen, again you can't build the proteins (RuBisCo etc) the plant grows poorly and is yellow and chlorotic. RuBisCo is the most abundant protein on earth, and it is where the majority of fixed nitrogen ends up.

cheers Darrel

 

[Bertie]

Hi Darrel,
Thanks for the info. I think I understand.

 

[ian_m]

Just a quickie though....when the plants start getting the "right" fert will the gsa already on the leaves die off or do I need to cut off the affected leaves,as I think on some of the plants they would be pretty bare afterward.

I generally remove the leaves if they get any signs of significant algae.

Also you can "rinse" the leaves in liquid carbon (diluted ?), I use Flourish Excel if you can get the plants out. Some of my anubias on wood leaves got covered in BBA, so hiked it out and wiped leaves with 50% Excel solution, left a minute or two and put back in tank. With in a day, BBA turned pink and was scoffed by my Ottos. Careful too strong and it attacks the leaves.

 

[Bertie]

Thanks Ian...I have plenty of liquid carbon so will hopefully sort it.