kekon

I'm not sure if i understand the question correctly... The level is at least 0.2 ppm. I always try not to keep lower values as it causes plants to have paler colors. Some time ago i confused Mg and Fe deficiency and kept 0.5 ppm of iron. Such high value didn't give any better results so it seems there should be 0.2..0.5 ppm in the water column.

Naja002

Hi Kekon,

I always look forward to Your posts and the results of Your experiments. This one right here on stunting is Exactly what I am trying to sort out right now. Your information is of Big Help.

I can Host the pictures You would like to put up on my website, if You want. There shouldn't be any bandwidth problems--my website is a pretty esoteric topic and I only get ~10 visitors/day. Just let me know. You can email them to me and I will upload them and You can link to them.

Many Thanx! for Your Efforts!

Bert H

Kekon thank you for a wonderful write up! I have a couple of questions for you. In your opinion/experience: 1. What has caused your most problematic gsa problems, dosing-wise? 2. What, if any, kind of symptoms (algae/stunting,etc) have you observed if you've od'd on micros, particularly Fe? 3. What, if any, detrimental effects have you observed in using higher PO4 levels, ie, N:P of 5:1 or more?

kekon

Hi, Bert H

I always had gsa (as well as gda) when NO3 and PO4 were too low but 10:1 NO3:PO4 was maintained. The problem appeared when PO4 was below 0.1 ppm and NO3 below 2 ppm. To get rid of gsa and gda i raised NO3 and PO4 to about 5 and 0.5 ppm respectively. The algae dissapeared usually within 2 weeks time.

The only symptom i observed when Fe was high, was gda and lots of brown sediments in the carnister filter. But gda appeared only when there was something missing - especially Mg or K.
When Mg and K were no longer limiting elements (in my case i increased Mg from 5 to 10 and daily K dose from 1 ppm to 2 ppm) all the algae disappeared - even at high Fe levels (about 0.5 ppm). I've never noticed stunting, toxicity etc. caused by higher Fe doses.
When it comes to other micros, i observed stunting when boron was overdosed (more than 0.015 ppm of B weekly)

Higher PO4 levels didn't do anything good... It didn't speed up plants growth nor it produced richer colors on plants. The only plant that seems to love higher PO4 in my tank is Blyxa japonica. When PO4 is at least 0.5 it constantly produces small flowers but they quickly disappear. I think 5:1 NO3:PO4 ratio (also 10:1) is quite good. The worst case is when PO4 is high and NO3 is close to zero. This causes gsa and gda.

Naja002

Maybe I missed it, but what is Your Water Change schedule? How much? How often?

Thanx!

kekon

Usually i do 35% water changes every week (on Saturdays) but sometimes i do 50% (especially when i make a mistake in fertilizing). I stress the importance of adding Fe and Mn to changed water. Other micros don't have to be added. I add 0.3 ppm Fe and 0.2 ppm Mn. When it comes to macro, i add 20 ppm K (per changed water volume) and 0.2 ppm PO4.

detlef

Kekon interesting statement that is. I'd like to know the reasons which made you think this way!

Would you therefore please elaborate a little more on why it is so important to (micro) fertilize changed water with Fe and Mn while omitting other trace?

Also, do you recommend dosing Fe all at once after the weekly water change or would you prefer adding Fe on a daily routine?


Best regards,
Detlef

kekon

Well, i add Fe and Mn not only after WC but also on daily basis (perhaps some folks may have misunderstood my fertilizing routine...)
The reason of such approach is the fact that doing 50% WC (or little smaller) greatly reduces Fe and Mn in the water column; they seem to be the most important micros for plants. The two elements precipitate very quickly - even when they are complexed by strong chelators. Manganese is more unstable than iron. I didn't take any water sample to laboratory to perform any measurements on manganese but some people i know did. It turned out that after adding Mn into the tank (for example, 0.1 ppm Mn) its level dropped very quickly - only after 3..4 hours the measurements showed 0 ppm of Mn in the water column !
When i added Fe and Mn (from TMG on daily basis; 250% dose) on daily basis only, plants usually became pale 3..4 days after WC. That's why i decided to add extra Fe and Mn after WC as well. Obviously if one notices that adding Fe and Mn after WC doesn't improve palnts colors it doesn't need to be performed.

Other micros seem to be much easier to dose. Molybdenum for example, is needed in very small amounts. I dosed Mo in the range of 0.001 to 0.008 weekly and it turned out that low and higher levels of Mo make no difference (there weren't any signs of deficiency or excess of Mo).
Boron - is very easy to overdose so adding it to changed water usually caused stunting in my tank (besides tap water also contains some boron).
Zinc - can cause Fe deficiency when present in high amounts but it seems it have very good effect on plants coloration. TMG has very little zinc and i think the creators of the fertilizer took into account the fact that tap water can contain some zinc (this is also the reason of not adding Zn after WC)

swoon

Hi Kekon,

First of all, thanks for providing such a great summary for all the testing that you have done. I've always found your posts very interesting and look forward to reading them.

I have just got a question regarding your findings. Now that you have tweaked the K, Mg, and Ca levels to eliminate stunted and deformed growth, did you then increase NO3 levels back up to a high level to see if that was the real cause of stunting?

kekon

Yes, i increased NO3 level up to 10 ppm and PO4 to 1 ppm when Ca = 45 & Mg = 10. At those levels the stunting wasn't as severe as when there were lower values of Ca and Mg (25 ppm and 5 ppm resepectively). However in a long term, even at higher GH the stunting returned but again, it wasn't so severe. It seems to me that in order to keep 10 ppm NO3 for example, GH must be at lest 8..10.
The higher NO3, the higher GH must be kept - it seems this principle is extremely important especially for many stem plants that tend to stunt at low GH and higher NO3. Rosette plants usually don't care about GH & NO3 levels.
However, having GH = 8 now i try keep NO3 at max. 5 ppm to entirely eliminate stunting. I realize some plants grow slowly at low NO3 but this can be compensated by adding 3 form of nitrogen into the tank (NO3 + NH4 + urea). Adding 3 forms of N work very well; despite many warnings from some people who say that urea and NH4 cause algae blooms. I can't see any algae in my tank when dosing urea and NH4.