Browning leaves

[Niton]

Hi.
In my 30 litre tank I'm starting to see a lot of browning of stems and leaves.



I'm dosing EI made up to APFUK recipe and dosing 10 ml of micro and macro on alternative days. Also about 5ml of FloraGrow Carbo daily.
Water changes are about 70 percent once a week, and about 3 litres of water to top up evaporation.

I'm running an 8 hour photo period with a Twinstar 300e at 70 percent strength.

Any advice on causes of this? Or parameters to look into?

Many thanks,
Nick

 

[Witcher]

Few possibilities I could think of: the first and probably most common one attributed to older leaves is lack (or not enough) of MgSO4 (epsom salts), 2nd one could be lack of N - usually accompanied by increasing patches of nearly translucent plant tissue and 3rd one could be lack of Fe - but in this case old leaves are affected by not enough of Fe at the stage of growth of young leaves.

 

[Jayefc1]

Agreed with @alto or it could be poor flow at substrait level

 

[Sammy Islam]

From what i remember, the APF recipe is 4tsp kno3, 1tsp kh2po4, 6tsp mgso4 mixed in 500ml of water.

Rotala butterfly isn't working for me right now but i would assume each 10ml dose to your 30l tank would give u about
9-11ppm no3
2-3ppm po4
6-8ppm k
2-3ppm mg

For a tank without without pressurised co2 i think that's way too much - the MG is probably fine. You should probably have a look at low tech EI dosing which doses like a 1/3 of EI i think.

Before i broke down my old tank recently, i let it run for 6 weeks without co2 and minimal ferts (from EI levels). To my surprise my hygrophila polysperma grew even better than before, but at a much slower rate. The leaves all looked much cleaner and brighter in colour and all i dosed was like 10ml of tnc complete twice a week.

 

[Witcher]

Before i broke down my old tank recently, i let it run for 6 weeks without co2 and minimal ferts (from EI levels). To my surprise my hygrophila polysperma grew even better than before, but at a much slower rate. The leaves all looked much cleaner and brighter in colour and all i dosed was like 10ml of tnc complete twice a week.

Hey @Sammy Islam - out of curiosity - what was the amount of ferts in ppm at 10ml x2 of TNC for your tank?

 

[Sammy Islam]

Hey @Sammy Islam - out of curiosity - what was the amount of ferts in ppm at 10ml x2 of TNC for your tank?

I assume it was a very low amount considering it was a 125l tank. Rotala butterfly isn't displaying for me right now so i can't check, but in general it would have been very low.

 

[Niton]

@Sammy Islam I was wondering that myself. Too much rather than too little. I'll halve the dose after tomorrow's water change and see how that goes. Thanks

 

[Sammy Islam]

I'm not sure what could cause the yellowing, especially seeing as you're dosing EI levels. It could be just old leaves that didn't adapt/grow well to begin with. I also think it could be diatoms as my rotala looks similar to yours - i'm currently going through the diatom stage and my rotala look brown lower down.

I don't think it's a deficiency as other leaves/plants look healthy in general, so i'm not sure what to suggest. But i do know that you probably don't need to be dosing full EI and could definitely dose half the amount.