I was wondering if someone can give me a little primer on what the typical symptoms of different nutrient deficiencies are. I'm pretty much clueless on this so when something goes wrong, I don't know what to do other than throw more random fertilizers into the tank. Like for instance - what to look for when plants have nitrate deficiency, potassium, phosphate, iron, magnesium, calcium.

I think it is rare that a tank has a single deficiency, making a look up table just about useless. If you are short of nitrate, you are probably short of potassium. If you are short of iron, you are probably short of all traces, and if you are short of CO2 that will hide any effect of being short of other elements. I prefer to just keep it simple, and rely upon the fact that fertilizing is not a job that requires precision. If you have double what is needed of any fertilizer, no problem. If you have triple what is needed, probably still no problem. So, I like to just be sure I have enough and am not dosing ten times what is needed, and I let the water changes keep it from getting out of hand.

I played around with reduced dosing for awhile, but didn't see any difference and couldn't justify continuing to do so, so I now just use EI, but dose daily (1/7th of a weeks supply each time.)

Vaughn, I just mixed stock solutions of my EI ferts so that I could dose the week's worth of ferts daily. However I divided the weekly amount by 6, because the EI dosing schedule calls for a rest day on day 7.

Is this "rest day" necessary? If dosing daily, would you still observe this, or just dose 1/7 the week's dose for 7 days? Or does it even matter?

(Sorry to change the subject Carissa )

-Mike B-

BTW, my stargrass plant is very particular about its nutrients.

I notice white new growth when I have low traces, iron, and/or nitrates.
I also notice the melting of leaves and stems on my M. Umbrosum and Stargrass when the nitrates get low. BGA also -COULD BE- a symptom of low nitrates.

I'm not sure about phosphorus. It seems to me that mainly P drives the uptake of the other nutrients, w/o actually showing a deficiency of itself in my plants. I do notice a decreased uptake when P is short, though. I have also read that GSA will show up when P is low.

People say they see pinholes in leaves when K is short, but I haven't noticed this in my plants. However I think I usually have enough of this and that is why I do not see this particular symptom.

I think Vaughn is right that CO2 really clouds all of these and low co2 could manifest itself in many different ways. From what I see Tom Barr post, low co2 is usually the problem when a plant is not growing well and shows symptoms. This makes sense, as carbon is such a larger percentage of the plant than N, P, or K.

Hope this isnt just obvious stuff that you already know. I dont want to patronize.
Hope it helps.

Good luck with the plants!

-Mike B-

I don't think plants do any resting, whether on the 7th day or on February 29th. So, I dose the same every day. I doubt it making any difference one way or another.

Thanks, that is helpful. However shouldn't the majority of plants grow fine without co2? That is, if other parameters are in balance? Are there plants that should never be attempted in a non-co2 tank?

High light intensity and CO2 go together. If a plant requires high light intensity to grow well, it also needs CO2. Plants that can grow well with low light can grow in a non-CO2 tank. That's how I see it anyway.

Makes sense to me. I guess some of these plants will live under lower light, but just not look their best.