Tips on growing plants and avoiding algae

[ChloroPhil]

I’m sure Wahter can shed more light on the subject, but here’s what I’ve come up with from conversations with experts and my own research. Algae are the result of an imbalance in the Nutrient-Light-CO2 cycle. Too much or too little of one or more of these will encourage the Green Monster to take residence in your prized garden. Being a lower plant species alga can get along on levels that the higher plants we’re trying to grow aren’t able to. Keep this in mind, it’s very important.

Let’s start with light and CO2. We all know that plants need sufficient light and CO2 to carry out photosynthesis. CO2 levels are pretty standard across the spectrum of plant species. The target range for CO2 is 18-24ppm which can be determined by comparing pH to KH levels. Check out www.thekrib.com or www.sfbaaps.com for references.

Most of the common “Discus friendly” plants can do well in moderate lighting. Just about all Echinodorus (Sword) and Cryptocoryne species in general do well with light as low as 2.0-2.5 watts/gallon [US] for a moderately high tank (18-24in.). Light intensity is the key here. The goal is to provide enough intensity to allow sufficient light to reach the lower leaves of tall plants and those species growing close to the substrate. With a tank higher than 24” lighting should be increased enough to compensate for the additional distance it has to travel. A good target goal for lighting would be 2.5-3.0w/g over the areas you’re trying to grow plants.

When light and CO2 are balanced and available in sufficient amounts for your plants they will be able to use stored nutrients to respire (create energy) and grow/repair tissue. When these stores are used up your plants will look elsewhere for what they need which brings us to the third part of the cycle, nutrients. While light and CO2 are relatively easy to get in balance and maintain; finding the appropriate amount of nutrients to supplement can be the challenge. More on that next.

[ChloroPhil]

Re:Answer to some algae questions...(long)

Each aquarium is a unique system that has equally unique nutritional requirements. A great primer on dosing levels was written by Tom Barr and can be found at www.sfbaaps.com. Plants require certain levels of nutrients to be able to function well just like they need proper lighting and CO2. An overabundance or lack of any one nutrient will open the door for algae.

Nutrients are grouped into two categories, Macro and Micronutrients. Macronutrients are just what you think they are, something plants need in large doses. These are: [N]itrogen (added as NO3), Potassium (K), and [P]hosphorus (added as phosphate, PO4) . Nitrogen and Phosphate are both known contributors to algae problems. Potassium hasn’t been found to cause algae itself rather; it is needed by plants to use the other nutrients effectively. Insufficient or excess levels of N and P and/or insufficient levels of K will give algae the one up needed to out compete the higher plants in a system. Check out Chuck Gadd’s website for a very useful dosing calculator.

Nitrogen is constantly being added to the aquarium in the form of Ammonia or Ammonium, NH3 or NH4, that substance all fish keepers love to hate. Luckily plants are able to use ammonia and ammonium very easily. In fact, a well-balanced and healthy system will use ammonia/ammonium the second it becomes available. With the generally low bioloads found in most discus tanks the amount of nitrogen made available this way are too low making supplementation necessary. The target level for NO3 is 5-10ppm.

   Keeping in mind that the best source of supplemental nitrogen is nitrate (NO3) we need to find a good source of NO3. This is easy to find as the gardening section of your local hardware store. Potassium Nitrate (KNO3) is the main ingredient in Stump Remover, just be sure to get a brand that is 100% KNO3. For those in the US Grant’s Stump Remover is available at most Lowe’s and Home Depot stores. A few dollars will get you enough for close to a year. I use ¾ teaspoon twice a week to achieve and maintain a level of 7.5ppm in a 90g aquarium.

[ChloroPhil]

Re:Answer to some algae questions...(long)

Potassium (K) is the next element on our list and is needed in the highest amounts of any nutrient. As mentioned above K is essential to the assimilation of other nutrients and the basic processes of a plant’s life. A deficiency in K will result in unused NO3 and PO4; the main cause of algae. Levels of 15-20ppm are what we need to achieve. I add 3/4tsp once after every water change (2x weekly) to maintain levels where they need to be.

Potassium can be found as a part of Potassium Sulfate (K2SO4) and can usually be found through a local agricultural or hydroponics supply company. Online vendors such as www.ecogrow.com or www.litemanu.com (US) and www.hydroponics.com (Canada) all sell this and other supplements as a dry chemical. Avoid purchasing liquid forms of Macronutrients whenever possible as it’s much easier to control levels using dry crystals or powders.

The last Macronutrient, Phosphorus, found in the form of Phosphate (PO4), is another of our love-to-hate substances. Luckily the types and amounts of food commonly fed to Discus are high in phosphate and should provide the necessary 1-2ppm. If supplementation is needed PO4 can be added by dosing with Monopotassium Phosphate (KH2PO4). This too is available through hydroponics or agricultural supply companies. A little of this goes a long way so an order of 5lbs is basically a lifetime supply. Another common source of PO4 is over the counter enemas. Just be sure there are no harmful chemicals when purchasing one of these.

Phosphate is often regarded at the cause of algae. In most low to moderately lit (1.5-2.0w/g) aquariums and/or those with slow growing plants this is often the case; as the Sears/Conlin study determined. In this case it is important to provide sufficient levels of light, CO2, NO3 and K, to allow the plants to use all PO4 as it becomes available. Doing so will make PO4 the limiting factor, helping your plants out compete algae for nutrients. It is worth mentioning that in high light/fast growing systems NO3 often a better limiting factor.


Just as plants need a supply of Macronutrients they also need a steady supply of Micronutrients also known as Trace Elements. These are common elements such as calcium, magnesium, and iron that all plants need, but in very low quantities. Of all the micronutrients only Iron (Fe) has been known to contribute to algae and then only if overdosed.

While there are dry trace element mixes available companies such as SeaChem and Tropica make high quality liquid additives. Unless one has a very large aquarium and/or one that has a high percentage of fast growing plants a liquid supplement is the easiest method. Dry mixes are available through most hydroponics suppliers.

[EthanCote.com]

Re:Answer to some algae questions...(long)

Wow Phils, great post. Thanx.

Now if only I can get you to come on over my place and set everything up for my plants, then all will be golden. ;D

But at least your posts will provide a basis steps for me to start. The problem is not to plant a tank, the problem is to keep the plants alive and healthy always had that problem. But am getting better.


Cheers,

Chi.

[ChloroPhil]

Re:Answer to some algae questions...(long)

Summary of Commonly Recommended Nutrient Levels~

Light: 2.0-3.0 w/g
CO2: 18-24ppm/20-30ppm (low/moderate-high light)
NO3: 5-10ppm
PO4: 1-1.2ppm
K: 15-20ppm
Fe: .1ppm (used as a rough measurement for traces)

Keep in mind that these are final target levels. Fishload and feeding routines will contribute to nutrients. Test your water often to ensure proper levels


I hope this helps!

[vosevichs]

Re:Answer to some algae questions...(long)

Thanks very much for the info. I was going to post a question about algae. It's growing alot better than my planks :'( I'm going to test my levels right now.

[Ralph]

Re:Answer to some algae questions...(long)

Do I give my discus the enemas? I have trouble getting them to hold still just to measure them.

Great posts, Phil! Your info fits in with some great advice I got one time to fight algae: Make sure your plants are growing. In other words, if you are giving your plants everything they need to grow (and not any more than that), then your algae won't have the nutrients to grow.

A couple of comments:
My tank proves your ideas on excessive lighting. Half my tank gets direct, though filtered, sunlight. The sunlight area gets algae and the other side doesn't. That is of course with the same water and same nutrients. The only difference is the extra light on the one side.

The nitrogen is a sticky subject with discus tanks due to the toxic nature to the fish of nitrates at higher levels. One of the principle reasons for WCs is removal of nitrates, so the idea of adding them will be a tough sell here. Generally though a target of 10 ppm of nitrates is accepted as a maximum so your levels of 7.5 ppm still fits inside that range. To hit that, do you take tests before and after adding the nitrogen?
I haven't added liquid fertilizer to my tank yet. My plants are growing though and I typically have 0 nitrates. I have a higher fish load than most here which would account for the healthy plants without adding nitrogen.

I am getting a phosphate test kit soon! And probably a potassium test too. Are they readily available?

I compared a trace element additive for plants to a trace element additive for discus and they were very close, so I just go with it.

I think I am going to make this thread a library type thread that will be permanently near the top (I have to talk to my co-moderators first though).

PS Some algae I really like.

[ChloroPhil]

Re:Answer to some algae questions...(long)

Ralph,

Even with a plant tank water changes are necessary although I got away with a lot in a crypt only tank. In my low light tanks I do 50% 1x/week. My high light tank (3.4w/g) is struggling with a Green Water epidemic so I do 50% changes 2x/week.

When I first started plants and was told I needed add NO3 to my tanks I was floored. When I realized that I had to add enough to keep the levels at a half to a third of what they were in a fish only tank I felt a lot more comfortable.

To be honest I haven't found a NO3 test that's sensitive enough to read 5-10ppm so I just add enough to achieve a pre-determined level. The great thing about KNO3 is that the ppm closely matches the teaspoon. .5tsp=5ppm etc.

I know Sera makes good PO4 and Fe test kits and I don't think a K test is necessary. Your plants make good indicators of K, Fe, and Trace levels.

I just realized that some of my dosing levels work for a very high light tank, but won't be appropriate for most tanks here. If you're going to post this in an archive let me change them. <fixed>

PS: I REALLY like Cladophora algae, it's the green velvety stuff that forms most often on wood, its gorgeous! I dont' mind algae on wood, rocks, and glass. As long as it stays away from my water column and plants I'm happy.

[EthanCote.com]

Re:Answer to some algae questions...(long)

Hey Phil,

I think I have some of that algae growing on my driftwood now. My Discus loves pecking at it ;D

The problem is, I also have some slimey green algae on the same driftwood and anything touching it likes plants or tank glass, will also get covered in it very quickly. That things is spreading like while fire. Will a bushy nose pleco take care of that algae?

Thanx.


Cheers,

Chi.

[ChloroPhil]

Re:Answer to some algae questions...(long)

Try SAE's (Siamese Algae Eaters), Crossocheilus siamensis for that algae if you have small leaved and/or delicate plants. A tank full of swords and anubias type a small bushynose will be great.

[joelfish]

Re:Answer to some algae questions...(long)

Wow, great stuff.

I want to emphsize the point about lack of nutrients causing algae. I see this so much. People are afraid to add nutrients because they have algae. They think that adding more nutrients will make the algae worse. It can be exactly th opposite. A nutrient poor tank is an opportunity for algae.

I used to be really afraid of adding nitrates. This is what we're trying to get rid of - right? My tank does much better now that I add some nitrates.

My final point, you can never starve algae of nutrients - it can get along on way less nutrients than your plants!

Joel Fish

[joelfish]

Re:Answer to some algae questions...(long)

Here's the result, now I just have to add discus!

[Ralph]

Re:Answer to some algae questions...(long)

Those are some healthy looking plants. Is that Java Moss growing on the wood?
How do you know how much nitrogen (nitrates) to add? What fertilizer do you use?

[ronrca]

Re:Answer to some algae questions...(long)

Thanks Joel! Tell us more about the ferts and nitrates! I need help with my tank though! It does have algae and I am one of those that does not add much ferts! Plants are doing good but algae..........!

I'll have to try it! Whats the worst that can help? More Algae? HEHe!

[ChloroPhil]

Re:Answer to some algae questions...(long)

Lovely tank Joel! Your Rotala could use a good trimming though, cut it in half and plant the tops in with the bases to get a nice thick bunch. Yes, while algae can get along on much smaller doses of nutrients healthy higher plants will outcompete algae for nutrients as they need much more and will use up available nutrients very quickly.


Ralph,
Yeah, that's Java Fern and Java Moss on the wood...isn't it pretty? I love that stuff.

http://www.csd.net/~cgadd/aqua/art_plant_dosage_calc.htm

There's a good dosage calculator. All the ferts are talked about in my sticky post, you need to use all of them.