Nutrients Question

[aquadude]

Hello everyone! I have always loved aquariums but I have never owned one and I recently acquired a 55gal tank. I decided to go with live plants and from my experience with plants I knew that the only way to go as far as light was HID. I found a posting on craig's list for a hood with 2 - 175-watt Metal Halide and 2 - 48" Florescent for $50 so I had to get it (don't everyone drool at once ). It came with 2 - 14k bulbs and 2 -10k bulbs and for the time being I am using the 10k bulbs until I have some money to buy the 6.5k bulbs. Since the 10k bulbs have more blues than I really need and not enough reds I used full spectrum florescent bulbs to help with the spectrums I am missing. Also I added a DIY co2 because I don't have the money for the nice system yet but I'm sure this is better than nothing. When I first put the co2 in I overdosed a bit (from watchin the fish) and I rigged up some air-line valves to control my dosing and it has been working great. My substrate is gravel (ouch) and I will be using something else when we move next year (cant wait). Since I have never owned an aquarium I wanted to get a variety of plants to see how they grow and handle different conditions and fish. Everything seems to be growing like weeds especially the Cambomba and Longiplumulosus. Anyways now to get to my questions. When I first went to the store to get some things to start cycling the clerk gave me API Leaf Zone and I dosed it for 2 weeks or so then noticed the Scarlet Temple was looking bad. Then the Red Ludwigia started showing signs of something bad. I tried researching all over the net and couldnt really find anything that was of any help. Knowing regular house/garden plants relatively well I guessed that the Scarlet Temple had a possible Mag deficiency and decided to see if that fert had any mag in it. As it appears it only has Iron and Potassium so I figured that must be the problem. I also had small amount of algae starting to grow on my Java Fern Lace which I then attributed to the fact that the plants werent growing because they needed some trace nutrients and that meant there was extra iron in the water causing the algae to grow. So it was about 3 days ago when I went and got some Seachem Flourish Comprehensive Supplement and I dosed the tank. Everything looks wonderful now. The Red Ludwidia leaves are all pointing up collecting all them nice rays and is growing like mad now. I was still curious about the iron though so today I finally found a iron test kit at a store by my house. According to the test my non-chelated and chelated iron levels are both0.0 mg/L. So my question is should I dose with the API fert to just add potassium and iron or should I use the Seachem. How often should I be dosing? I will try to include a pic of my tank so you guys and gals can see what I'm workin with Any suggestions are much appreciated. Oh and in case anyone was wondering where the Scarlet Temple is.... I had to bury it :*(

 

[Carissa]

Wow...overdosing diy co2 on a 55g? What kind of setup do you have? I would love to have that problem. If you're sticking with diy, get a drop checker, it's really the only way to do diy successfully since you will know right away when the co2 level starts to get low.

I'm not really sure how to answer your specific questions as I only use individual powdered fertilizers, but you will need to be dosing nitrate, potassium, phosphate, iron and traces; and calcium and magnesium too if you have a low GH (or GH booster). With high light and co2 it's not likely you will get away with not dosing any one of those things for any length of time, although with as few plants as you have in the tank right now you might be ok for a little while until they use up their reserves plus whatever is in the tank for whatever you're not dosing.

I also don't know much about metal halide bulbs...but the general idea is that for a co2 tank with fluorescent bulbs you want around 3 wpg, 4wpg maximum. Any more than that, and you're just growing extra algae, usually.

 

[aquadude]

Thanks for the reply! I realize I am not using the ideal ferts but I'm working with what I have right now. I do plan on buying bulk dry ferts in the near future. The thing I'm really trying to adjust to is how the plants differ from growing regular plants with hydroponics. Obvious differences are that the entire plant mass is submerged not just the roots and we now also have fish to deal with. I do know that with the hydroponics it is possible to have a nutrient lock-out by adding new water/ferts to the old water. This is because the plant may not have used much of a given nutrient and by adding more of that nutrient it can somehow block the absorption of other nutrients. Is this also the case with aquarium plants? Also my lighting being around 7wpg I know is a little excessive but its either that or IMO I will be lacking any decent lighting by just using florescents. I'm not crystal clear what affect the water has on the light but I do know that florescent bulbs only have about 2" of good light penetration. I am in no way thinking I will have an algae free aquarium but I would like to keep it under control. I do stager my lights so that the florescents come on a couple hours before the halides and go off a couple hours after the halides. As far as adding the ferts, I did a 40-50% water change last night and I had to add double the dose of the leaf zone to even get a reading from the iron test. So does this mean I will also have to dose extra micro nutrients as well? Someone please help shine some light on this for me. Oh and dont think I havent spent the past month reading everything I can possibly can because I definitely have

 

[Carissa]

I don't know of any type of lockout that happens if you add ferts. Most people here do the EI method, basically overdosing and then doing a 50% water change to reset the nutrient levels so they don't get harmfully high. Just make sure you are adding all of the ferts the plants need....with high light driving the nutrient uptake you can bottom out very quickly if you are not dosing adequately. Signs of bottoming out are often algae (usually the first sign), then progresses to holes in leaves, leaf loss, spindly growth. If you are not dosing all the macros/micros as listed above (check the bottles to see what you are adding), you should really reduce your lighting until you can provide the nutrients the plants need. Light intensity drives nutrient uptake. Otherwise it's pretty likely they will start dying off. $20 gets you all the powdered ferts you need for a year, much cheaper than replacing all your plants and probably a lot cheaper than buying what you currently have.

Explain your diy co2 setup.... it's usually not possible to do diy on a 55g and get nearly enough co2. If you get a drop checker, you'll be able to monitor co2 in almost real time. $10 on ebay.....again a cheap purchase compared to the cost of new plants. On my 32g tank, I have the co2 running with 2 - 2L bottles and a continuous stream of bubbles coming out getting diffused into my internal filter, filling the tank with micro bubbles from end to end 24/7. I've never been able to get too much co2 with this setup, my problem is usually the other way around.

 

[VaughnH]

The exact amounts of each fertilizer in a planted tank are not critical. You do need an adequate amount of each, but having twice that much isn't a problem. Leaf Zone is just a trace element mix, providing no nitrate, potassium or phosphate to speak of.

I strongly suggest you put the test kits on a high shelf where you can look at them but not reach them. Then follow a fertilizing routine to be sure you are providing for the plants needs. Many of us use the "estimative index" routine, which is well described in an article here, and which relies on weekly big water changes to get rid of whatever excess fertilizers we have added. There are other routines which have worked for other people, too.

You also do have far too much light, unless you raise the MH bulbs well above the water, but that will spill a lot of light into the room. Fluorescent bulb light "penetrates" just as deeply as MH light. Light is light - the source is irrelevant. What determines the "penetration", which actually how much the intensity drops with distance from the light source, is the quality of the reflector being used. T12 or T8 fluorescent tubes are so large in diameter that you can't design a reflector that can direct all of the light down into the tank, so the intensity of that light drops pretty fast as you move away from the source. MH bulbs tend to have better reflectors, so much more of the light is directed into the tank and the intensity doesn't drop off as fast with distance. T5 bulbs are small enough in diameter that you can use parabolic reflectors to direct a much higher percentage of the light down into the tank, and the intensity doesn't drop as fast with distance.

A lot of people have had very successful tanks with only T12 lights over them. I used to have a 120 gallon tank with 8 40 watt T12 lights, which grew very well, especially considering that I used very little DIY CO2 and only trace element fertilizing.

If you can do it, I suggest replacing the MH lights with 70 watt lights.

 

[aquadude]

First off, according to the bottle Leaf Zone has only Iron and Potassium. Am I missing something? My metal halides are about 7" from the bottom of the bulb to the top of the water. Yes light spills into the room and no it is not an issue. My co2 setup is 2- 3liter bottles going into a ceramic diffuser that is located below my filter intake. When I originally overdosed the tank I had my line going directly into the filter intake so I'm sure it was close to 100% efficiency. Most of the larger bubbles still get sucked in and I dont get the noise from the pump. Im not sure if you have ever grown plants with artificial light but if you grow with a florescent bulb and the bulbs are not within around 5" of the plants they will stretch out to get to the light. That is what I meant when I was talking about the penetration. Like I said I am new to this and trying to figure this stuff out as best I can and I do appreciate all of your input

 

[Carissa]

So it sounds like you need to find sources of phosphate and nitrate unless that's in the Flourish. What you should do is figure out how many ppm's of each nutrient you are adding to the tank when you add x amount of each fertilizer, then you can post that info and it will be easier to figure out if you need to be adding more.

You need to be adding:
Nitrate
Phosphate
Potassium
Iron and traces
possibly Calcium and Magnesium if you have low GH

 

[tv205]

Aquarium plants do not require anywhere near as much light intensity as hydroponically grown crops. Yes, hydroponics requires plants to be very close to a fluorescent light source, but aquarium plants get by very well with just fluorescent lights in standard sized aquariums. Unless you add enough fertilizers, including CO2, to keep the plants growing like weeds, you will most likely see major algae issues at that high light.

 

[aquadude]

Just curious as to why everyone seems to have a different answer for the cause of algae? Oh and for what its worth the small (very small) amount of algae that grew on the glass made a line around my tank about 8" from the top where not a single bit of algae grew.... Guess it was too much light for it eh..

 

[Carissa]

There are many things that lead to algae. Ultimately, it's often an imbalance somewhere with the light/co2/nutrients and specifically their ratios to each other, or an unstable environment where co2 is fluctuating (the plants are unable to adapt fast enough when conditions change constantly). There is also a lot of misinformation out there, especially the idea that algae is caused by having too many nutrients in the water. It's true that it can be caused by having too much organic waste, but adding inorganic nutrients does not cause algae growth in and of itself, many people on this board add large doses of inorganic nutrients frequently and have nearly algae-free tanks. Rather, when diagnosing an algae problem, it's better to look at what might be out of balance that is causing the plants to become unhealthy....light to co2 ratio, low nutrients, not enough water changes, etc.

If your light works....go for it! But in my experience, algae will rarely grow seriously in a newly established tank, it seems that it takes time to establish whatever conditions it needs to grow or maybe to get the algae colonies big enough to reproduce quickly. But once it does set in, the higher the light, the faster it will grow. Unfortunately, there's no such thing as too much light for algae (in general). Sunlight is far brighter than any artificial lighting, and algae has no problem growing under sunlight.

 

[aquadude]

This all makes sense. I was just throwing out an observation But I'm still not convinced that the higher light will make MORE algae grow. With higher light things just happen faster all together and more maintenance is required. The plants grow faster and does the algae when something becomes unbalanced. So basically from everything I have read the extra light is not really a problem if I am willing and able to keep up with the tank maintenance. Is this the correct assumption? Oh and to tv205 can you explain what happens to the light as it enters the water that changes the intensity required for the plants? Not sure if I said that the right way but I'm still curious why a florescent has to be right on the plant out of water and why it apparently doesn't matter how far the plant is from the bulb in water.

 

[Carissa]

Higher light does indeed make things go faster, you are totally right on that. But the thing is that once you get beyond a certain amount of light (maybe 4wpg) it's just far more light than the plants can use even with co2 injection, it doesn't speed anything up anymore so it's just free game for algae to use.

I'm not totally sure on this, but I would think that aquatic plants simply don't need as much light as many terrestrial plants since they always grow, well, underwater, where they don't get as much light anyway. Even plants that grow in water lit by direct sunlight still don't get that much light since the water reflects so much of the light, and then you have particulates in the water, surface plants/algae, etc. which we may not have in our relatively shallow clean tanks, that all gets in the way of the direct sun before it reaches the plants.

Someone correct me if I'm wrong, but what I was reading on another post here the other day was that after you get beyond the first few inches of water, the lighting intensity just gradually drops as you get below that point. So only the top few inches are really bright, and the rest not so bright.

 

[VaughnH]

Every light we can use will show a drop in intensity the further you get from the bulb. In theory, a bulb that is long an thin, like a T5, will lose intensity about proportional to the distance. But, a "blob" source of light, like a screw-in bulb, will lose ligh proportional to the distance squared, so that shape of bulb will provide a much less intense light at the substrate level.

Tomrrow I plan to borrow Tom's PAR meter and do some testing to try to see if those theories are correct, and to try to settle my question about how to get "high light intensity" in a ten gallon tank. I will be posting my results here.

The question about whether or not higher light means more algae seems to me to be settled. The more intense the light, and the longer it is on per day, the more likely you are to run into algae problems. Of course you can still avoid the algae by fertilizing, providing good CO2, good water circulation, good cleanliness, and enough growing plants for the volume of water involved. People do use very high wattage lights without algae issues, so it can be done. (Look carefully and you will notice that those people have a faint halo above their heads )