Diving into plants (more like a belly-flop)

mcps95

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Jun 16, 2004
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Redmond, WA
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So, I've been working on adding plants to my already-established 55 gal community tank for a while now, trying (foolishly) to "get by" with the original 0.5WPG lighting with limited success, then biting the bullet and upgrading to 2.3WPG with a FW Coralife strip light. I've got mostly Anacharis and a slightly chewed-up sword (looks like a melon sword, but not positive) left now after all my trials, and at least the Anacharis seems to be doing well (not quite lush, but certainly growing taller very quickly).

Of course, this is all leading to a question...

Since I started adding plants and keeping the tank lights on (both 0.5WPG and now 2.3WPG) for 12 hours a day (on a timer), I've had routine outbreaks of diatom algae. I know it's easy enough to clean off, but with the amount of decor and plant surfaces, it takes a while to "un-brown" the tank. The answers I've read regarding diatom algae relate to it only occuring in new tanks (mine's certainly not) and due to insufficient light/photo period. 12 hours a day seems to be on the high-end of the recommended photo period range, and 2.3WPG seems like a reasonable amount of light for the plants I'm looking to grow. When I did upgrade to the 2.3WPG strip light, the problem seemed to have compounded, contrary to the suggestion that less light causes diatom algae blooms.

Here are some of the relevant specs:

Tap water:
Nitrate: 0ppm
Phosphate: 0ppm

Tank water (last water change: 3/31 - ~40%)
Ammonia and Nitrite: 0ppm
Nitrate: 0ppm
Phosphate: +10ppm (off the chart for the test kit - Aquarium Pharmaceuticals)

I'm just guessing, but it looks like the lack of Nitrate might be the problem in the sense that the plants are using up all they can and the diatoms take over using all the excess Phosphate when the plants can't compete. I've purchased Flourish Nitrogen, but after reading the container, it seems the recommended amount won't really increase the Nitrate level in the tank enough to satisfy the 10:1 Nitrate to Phosphorus rule (or it could just be a problem with my math).

If my thinking is correct, what amount should I use to help prevent the diatom blooms? If I'm not correct, could someone point me in the right direction?

Any info is greatly appreciated!

Mike
 
Fill the triangle

I just recently went to a planted tank about 2 months ago and am in my own battle with algae (I'm currently winning). From what I have read and from my recent experience you need high light, ferts, and CO2 in balanced amounts to combat algae. Your plants need these to adequately outcompete the algae. I don't see anything in your post about CO2. It isn't as hard as it seems and it does incredible things for plants. All of that being said I have to admit that the easiest fix to diatoms is a group of mightly ottos. These fish are awesome at removing them. I had 1 completely clean out a very brown 20g.
 
With the somewhat high bioload in my tank, I'd like to reserve adding Ottos as a last resort.

I understand that light, ferts, and CO2 are all important for keeping plants, but I have yet to see any definitive information on amounts and ways of determining if these things are in balance. I've read the stickies in the Aquatic Plants forum on ferts, but it doesn't give amounts per gallon, instead generalizing with "just add this." This doesn't seem very reasonable to just arbitrarily add ferts to a tank without knowing the current water params, lighting, and what is growing in the tank. Also, there doesn't seem to be any way of testing for CO2 level or certain ferts (other than nitrate and phosphate). How could you dose something if you don't know how much is in there already?

I don't currently add any CO2 to the tank. I will consider it down the road, but at this point my main focus is correcting the algae problem, which doesn't necessarily seem to be the cause of the issue.

Any insight is greatly appreciated.

Mike
 
Well here's the problem. There is no standardized water so pretty much every town and city has different parameters. So in the end it comes down to experimentation with dosing, err on the side of caution, and the plants will let you know what they are lacking. Yes, this can take a while to figure out your weekly dosing schedule.

We have access to PO4 and NO3 test kits and we can calculate CO2 from your pH and KH values. But this is a start because it's generally accepted that a 10:1 N to P is good. For the other macro, potassium, we can't test. The other important factor, trace elements, can't be tested for either and the dosing really depends on lighting, CO2, plant types, etc. I actually dose fairly heavy on this stuff at about 50ml per week of CSM+B. There are other ferts such as calcium and magnesium that you may or may not need to add but your plants will show deficiencies if they are lacking.

I'm sorry if this all sounds like a lot to take in but everyone here started somewhere and persevered. Nobody can really tell you how much to dose, but only what your plants need to survive. A report from your local water company will tell you how your water is made up.

Also, this is the reason why so many plant enthusiasts do large volume water changes. It prevents build up of excess nutrients and resets your tank for the next round.

One more thing. When I first started experimenting with plants on my old 20g, I also had an outbreak of diatoms even though the tank had been running fish only for a year. Because plants are living things, they will have an impact on your water readings, just like your fish.
 
I am no chemist but it strikes me that the plants themselves are raising the phosphates and essentially feeding the diatoms at this point. They always die off some in a tank, some things are always wilting etc.
But if your tap water has 0 and the tank has 10 then it seems you might simply do some water changes.

I think there are a lot of people who optimally tune aquariums for plants just like Discus keepers optimally tune their tanks for the fish. This allows them to grow anything they want. I don't think you have to do that. Though, It is probably better

Early on in this process it is pretty easy to figure out what will grow. You just do a little research and add plants that are easy and fast growing. Wipe the diatoms off the glass for a week or so and then the easiest thing to do is add some otocinclus. Now if things are going well you add more plants. At that point most likely you will encounter some green spot algae, again you need to add more plants. You will see right away that the green algae grows on the plants and the leaves of the plants that are not growing quickly. You need to starve it.

I tend to do things from experience and not from chemical test kits. So I am probably not the best person to comment but one of the things I do as this process starts to succeed is slow down the filtration in the tank. I don't know the chemistry behind that but I assume I am raising the N in the tank and giving it to the plants rather than the bacteria.
 
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