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Nutrient Deficiencies and Nutrient Excess in Planted Tanks
By Joe Anderson

NUTRIENT DEFICIENCY IN AQUATIC PLANTS

Since my philosophy involves doing things at a slow to moderate pace, I haven't had too many experiences with Nutrient Deficiency Problems. However, I haven't been totally free of problems. When I upgraded my lighting on a 20 gallon high to 4 watts per gallon I began to see more rapid growth which led to several nutrient problems. The lack of an adequate CO2 system also contributed to my problems. Aquatic Plants need a balance of CO2 and Lighting. In my case the lighting was in excess of the necessary CO2 (since for a while I was not adding any).

My plants first developed Magnesium deficiency as observed by stunted growth and light green to yellowish coloration on normally vivid green leaves. These same symptoms also can be attributed to Iron deficiency, so a small test amount and a good week or two of patience is required to positively identify the deficient nutrient. Next, I began noticing signs of Potassium deficiency. Leaves of some stem plants developed brown spots ("burn hole") on their leaves and Hygrophilia difformis leaves were down-pointed and showed slow and/or stunted growth. It was at this time that I was adviced to cut-back on my lighting and upgrade the CO2 production. Likewise, it was recommended that I cut back on the Magnesium (MgSO4 Epsom salts) and Potassium additions (Tetra Flora-Pride with Iron and Potassium) until the plants could regain their balance.

My initial routine now was to use Epsom salts (MgSO4) for the magnesium and muriate of potash (KCl) for the potassium. In this way I avoided adding excess Fe. When I felt I need the added iron I resorted to the Florapride. I also occasionally use Kent's Essential Elements for marine tanks for any needed micro and/or trace elements that I feel I may need. This formula also contains Potassium, so I use it when my K levels are low and I feel as though I may need to add trace elements as well.

On my current display tank I do not have to fertilize too much because of the kitty litter substrate, all the iron I'll ever need is already present. I do inject CO2 via a 5 lb. cylinder directly into an intake on one of the two canister filters on that tank. I also change 40% of the water weekly and add 1/4 tsp of potassium sulphate with every water change and 1/2 tsp of epsom salts with every other water change.

I discontinued using the muriate of potash for potassium because I believed it to be the reason for my mysterious shrimp die off.

Pinpointing which nutrient(s) is/are limiting plant growth in an aquarium can often be quite difficult. The links to Nutrient Deficiency Signs below are helpful in identifying nutrient deficiencies in your plants. Good plants to include in your aquarium as indicators of particular nutrient deficiencies are listed below.

Red stem plants such as Alternathera reineckii and Ludwigia repens are good indicators for iron deficiencies. The red coloration of their leaves requires a strong level of both light and iron. An iron rich substrate and at least 2 watts per gallon is the best solution to this problem.

Fast growing stem plants such as Hygrophilia polysperma and Cabomba make great general indicator plants. If they stop growing at their regular speed and size then you can bet something is wrong somewhere.

Floating plants such as Riccia fluitans, Ceratopteris, or Duckweed are good indicators of Nitrogen levels. If these plants start to take over the surface of your aquarium then nitrogen levels are way too high!

Deep substrate feeders like Echinodorus species and Cryptocorynes are good indicators of adequate Macro element fertilization. If these plants are stunted in growth then they are not getting adequate supplies of either Nitrogen or Potassium.

With this information in mind and a little patience and experience, one can more readily determine his/her needs. The most important thing to remember is to go slow. If you suspect a particular nutrient deficiency after reviewing the charts and or other material, you should add only a small amount of the suspected deficient nutrient; say 1/4 tsp to every 10 gal.
Do this for about 3-4 weeks and observe the effects. If the plants seem to perk up, you know you've got the right nutrient and you can increase the doseage slightly.
Remember, that by adding one nutrient, you can also create a deficiency in another. The trick is to attain a balance. KNOW YOUR TAP WATER PARAMETERS, and your own personal goals. With some idea of what you are shooting for, and what you've got to work with, you can more effectively adapt your fertilization regimine for success.

ALGAE AND EXCESS NUTRIENTS

Phosphate:
Less than .5 ppm seems to hurt the plants but more than 1 ppm can lead to a BBA outbreak. (Black Brush Algae, the worst!) Overfeeding, insufficient water changes, and too many fish can cause high PO4 levels. Your local tap water can also be the culprit. Check levels. Anything over 2 ppm is too high.

Iron:
Too much Iron can cause a soft beard-like algae or thread algae to grow on your plants. The beard algae is very light green and is particularly enjoyed by SAEs. The SAEs will also eat the thread algae. The thread algae may be the early stages of the light green (beard-like) algae mentioned above.
Another type of algae that may be brought on by excess Fe levels is a short furry green algae that grows on brightly lit leaves. You'll need to cut the affected leaf away and/or cut back on the iron.

Nitrates:
Too much nitrate can cause green spot algae and make just about any algae problem worse.

Silicates:
High Silicate levels will cause the brown film algae that is usually noticeable in newly setup tanks or those with poor lighting. Strong light seems to prevent this by increasing the levels at which the plants use this nutrient. Octocinclus affinis seem to love this stuff.

MUCH OF THE INFORMATION ABOVE WAS CONTRIBUTED BY ANDREW BOLLING

GREEN WATER REMEDIES Listed below are several reported remedies for green water. Green water generally is the result of excess nitrates in connection with too much light.

• freshwater clams are natural filters of green water - suspended algae.
• daphnia are another natural remedy.
• use of a diatom filter to filter out the suspended particles.
• increase the nitrate levels. Though this sounds illogical, if you have some experience with the use of fertilizers, this may be a avenue for you. **But, this is only for the experienced aquatic gardener!
• darken tank. Limiting the light is the generally accepted simple solution. If this does not work, identification of the problems in your tanks water parameters may lead to the use of another remedy either in conjunction with darkening the tank, or alone.

• FREQUENTLY ASKED QUESTIONS @ The KRIB
• LOTS OF AQUARIA INFO, but lots of reading
• PLANT DEFICIENCY SIGNS@ the KRIB
• PLANT DEFICIENCY CHART@ the DietschZoo
• PMDD PAPER A MUST Read for any aspiring aquarist. Outlines procedure for making your own fertilizers.
• Comments on the Above Paper.
• PMDD Ingredients Broken Down, so you can be able to find them easier.
• PLANTGUILD SITE Just in case you don't want to make your own, you can purchase pre-made pellets here courtesy of Mr. Bill Terburg!

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