Question About Light In Relation To Plants

[Byron]

Some shrimp are fine in softer water, according to what others have written.  I've no knowledge of shrimp so will leave this for the experts.  But as for adding calcium, first ascertain the GH of the tap water; this will be mainly calcium and magnesium, and may be sufficient on its own for your shrimp species.  You have soft water fish in both tanks mentioned, and while raising the GH a bit may be fine, without knowing what it now is we can't say.  Keep in mind that the higher the GH, the harder the water, and this does impact the physiology of fish.  I'm not saying they will die, by no means, but fish like rasbora and neons will work harder in harder water, and the softer the water, the healthier these fish will be.
 
In my own tanks, three of them get Equilibrium to raise the GH from near zero (the tap water is very soft) to around 5 dGH.  This is solely for the plants, specifically the swords, aponogeton and tiger lotus which show serious calcium deficiency symptoms without.  I've no idea if this is sufficient for various shrimp species.
 
My copper harlequin rasbora, Trigonostigma hengeli, are in my 33g which has zero GH and KH, and a pH below 5, and they are thriving.  This species is wild caught, but I would not think it would have difficulty with 4 or 5 dGH, but in this tank I only have Java Fern, one crypt, moss, and floating Water Sprite and Water Lettuce, and raising the GH is not needed for these, so fish and plants are happy.
 
Byron.

 

[DrRob]

Old article, but has a bit of simple maths and suggestions for a mix.
 
http/www.theplantedtank.co.uk/RO.htm

 

[Zikofski]

okay my GH and KH for my tap water is between 0 and 1, now once i have added my EI salts, including MgSO4 my GH and KH rise to between 5 and 9.
 
in my Iwagumi tank the only plant i have is cuba and i am getting very good growth from that plant, i mean good growth, now there is only one thing i am doing differently in this tank to my 88L tank and that i put the 3w bulbs closer together so the lighting is more dense, the tank is more taller but still with the stronger light i seem to get good growth. as i am getting good growth i am not to fussed about increasing the GH and KH in this tank.
 
the 88L tho, gain same results but again the lighting is less dense, for example each 3w bulb is say 10cm apart from each other where as in the Iwagumi tank its only 5cm, this is why i asked the question about lighting being to low. seeming that i am getting good growth on stems, anubias, crypts, VERY good growth on crypts, but i am getting new growth on DHG and Valli, but like i said its staying low, very low, now if that is a lack of calcium then thats brilliant i shall add that
 
thank you DrRob i shall read that now