Under dosing...

[maanse]

Hi guys,

Im having a bit of a problem with ferts in my tank, i think im under dosing on something. The problem i have is that my plants seem to loose a lot of (green) leafage and a lot of leafage seems to die off. It seems that the older leaves tend to yellow and die off and some of the newer leaves drop off, every day i find a little more plant floating in the tank. The growth that isn't dying or dropping off seems ok but of a fairly pale green and some plants exhibit black spots.

Overall plant growth doesn't look all that lush.

Set-up:
Fluval Roma 200 with U4 internal filter and an old stingray 15 for circulation and stock lighting (2x 30w T8's)
Im using a diy yeast based co2 with a green co2 indicator.
Ferts: im following the solution on james's planted tank (is it down) which is made up of -
48g Potassium Nitrate
2.2g Potassium Phosphate (monobasic)
17g Magnesium Sulphate Heptahydrate (Epsom Salts)
0.5g E300 Ascorbic Acid
0.2g E202 Potassium Sorbate
5g EDTA Chelated Trace Elements Mix
500ml distilled water

and im dosing at 20ml/day.

I did have some 2 month root tabs in the substrate and plant growth seemed healthier and didnt drop anywhere near as much but they have dried up again and im back to the same problem. What ever was in those tabs helped massively.

Any ideas how i can try and pinpoint what im missing without having to keep replenishing root tabs.

thanks in advance.

 

[CeeJay]

Hi maanse
Welcome to the forum.
First question, how long is your lighting period?

The growth that isn't dying or dropping off seems ok but of a fairly pale green and some plants exhibit black spots.

Following these observations, my guess would too much light, (lights on too long), and not enough CO2.
If we bombard the plants with too much light, the demand for everything like ferts & CO2 goes up. If we slip up on just one part of the equation, it all comes tumbling down.
The black spots you mention are probably the start of BBA which is a sure sign that the CO2 is not up to scratch and more than likely, unstable.
Your flow may be an issue too. A general rule of thumb is that we aim for 10 times the tank volume turnover per hour to circulate the CO2 and ferts effectively. On your tank that would equate to 2000lph, which, after a bit of digging round the internet, tells me you have around 1300lph, and that's without any media in the filters , so you have far less than this.
Try reducing your lighting period to start with and move the CO2 indicator around the tank and leave it each position for 3-4 hours at a time and see if it still stays green. If it doesn't, then you have CO2 issues.
Another question, are you using 4dKh in the CO2 indcator?
There's a few things for you to investigate for starters. Let us know how you get on, and just holler if you have any more queries.

For your info. I'm using that very same mixture on 2 of my tanks tanks and it works well, once you suss the dosing levels required.

 

[Anonymous]

Try and reset also your water parameters doing a 100% water change using dechlorinated water (not all at once of course), fertilize your tank again to optimum levels then keep your water changes at 50% at least weekly if you didn't do that already.

Cheers,
Mike

 

[maanse]

Hi guys,

Appreciate the reply's.
OK first off, At the moment the lighting is on for 8 hours p/day. I have thought about reducing this but didn't want to make matters worse. As for the black spots, they look more like pin head sized dead patches to me, at first i thought it was fish waste but it didn't rub off.

I had a feeling that flow may not be as desirable as it could be but funds have stopped me there, i am looking to replace the filter with an external in the not so distant future so im hoping to get a decent one with a high enough turnover. Any cheap alternatives in the meantime??

With regards to the 4dkh in the co2 drop checker, i haven't bought a 4dkh solution, but my water is 4dkh so i assumed that was just as good.

First job tho is im limited for time this morning..... reduce the lighting to 6 hours.

Thanks again.