Please could someone check EI dosing

[amy4342]

Hi all
It's been a really long time since I posted here - I've been out of the hobby for a good few years. It's so good to be back

I was lucky enough to pick up a display model Aqua Oak 450l systemised tank and cabinet with a damaged tank, so they replaced the tank with an opti-white non-systemised version. Absolutely perfect!

It's been set up for five weeks and it's looking ok. There's no livestock at the moment so drop checkers are yellow by the time lights come on and most of the plants are swaying gently due to a full spray-bar along the back, so good CO2 distribution I think. A bit of brown algae but nothing bad. I'll get some pics up soon.

I was wondering if someone could check my EI regime and answer some questions please. I'm using pure RO water. I've come up with mixing 35g of KN03, 6g of KH2P04, 60g of KS04 and 110g of MgS04 into a 500ml bottle and dosing 75ml each time. Does this sound right to people? I'm a bit concerned about exceeding solubility. I also won't be able to change 50% of the water each week due to my RO container not being large enough - I'll be changing 25% each week.

I'm also aware that I need to raise the GH and KH. I'll be using James' remineralising recipe. Does this mean I should adjust my EI recipe? I'm assuming that I won't be raising the GH and KH by the same amount each week though so again that would mean changing the EI dose each week. This is such a minefield!

So grateful for any contributions . Thanks all!

 

[EdwinK]

Here is a link that helps you calculate your dosage - http://rotalabutterfly.com/nutrient-calculator.php If there will be a solubility issues you'll get the alert. I am not aware of James' remineralising recipe but probably you will need to adjust KNO3 if using a Ca(NO3)2x4H2O and your dosage of MgSO4x7H2O

 

[ian_m]

You need to just remineralise your RO, best & cheapest way is to cut 50:50 (or similar) with tap water and just dose EI. At 450litres & 50% water change per week, you will need to reduce your RO usage as it will cost a fortune. If on water meter and you have a reasonably efficient RO unit, with booster pump, you will be looking at 1.5p per litre RO cost, excluding all the membrane, prefilter, filter and DI costs (and Prime dechlorinator). Why are you requiring to use RO ?

All people that have "invented" their own dosing scheme, end up with plant health issues

 

[amy4342]

Thanks both for the advice!

I've used the rotalabutterfly link to calculate my dosing - so easy! I think I may switch to dry dosing actually - measure doses into little pots - will be so much easier.

Ian, I switched to RO water years ago after I started having issues with livestock, and this solved my problems at the time. I'll be adding Discus soon so I'll be sticking to the RO water. Luckily, I'm not on a water meter , so it's only the cost of membranes and filters, which I'm prepared to pay.

I'm actually thinking, the magnesium from the EI will raise the GH, so I may just add some potassium bicarbonate to raise the KH, and reduce the amount of potassium sulphate I dose. Does this sound right? Also, do I need to add calcium?

Thanks for any help

 

[ian_m]

EI doesn't normally have potassium sulphate ?

Yes to adding some Ca.

 

[amy4342]

Oh drat! Then why am I dosing 6g of potassium phosphate and 60g of potassium sulphate?

Brill, I'll add some Ca. The rotalabutterfly calculator suggests I add 23g of CaSO4, which will give 15ppm of Calcium and raise the GH by 2dkh. This seems like a lot to me?

I'll also add some potassium bicarbonate to raise the KH. I'm thinking, I'll be keeping the GH and KH low, so I won't adjust the EI mix at all, I'll just add on top of this.

Does this sound good to people?

Thanks!