Too many nutrients????

[mackdaddy81]

I am having an algae problem in my planted tank and I need some advice. Right now in the tank I have three fancy goldfish, about 12 to 20 ghost shrimp, and a rubber lip pleco. The tank is 29 gallons and it is heavily planted. Every week I dose about 5 ml of an iron fertilizer called Plant Gro and I change about 7 gallons of water. I also have about 5 flourish substrate fertilizer tabs in the gravel. I inject CO2 with a 2 liter DIY CO2 injector. I have 4 CF lights, 2 20 watt 6500K and 2 15 watt 6500K bulbs. I leave the lights on from 6 am to about 8 or 9 pm. The rubber lip does a pretty good job of getting rid of the algae on the glass, but my driftwood and plants are getting over run with algae. Some plants seem to be flourishing like my anachris and wisteria, but the bottom leaves of the wisteria are covered in algae. Their is hair algae and regular green algae on my driftwood, microswords, red ludwiga, and corkscrew vals. Every day I see more leaves from the red ludwiga floating at the top, and some of my microswords look like they are dieing, while others look like they are spreading. I am really confused and could use some help.


Thanks!

 

[neilanh]

What you're experiencing is a nutrient imbalance, I bet. I'm not familiar with the Plant Gro you're using, is it only an iron supplement? You need to balance out your nitrate, phosphate, potassium and iron/traces.

What happens when things are out of balance is that the plants won't utilize the nutrients efficiently. Therefore, you end up with all this excess of some nutrient, that the plants can't use because they're missing the other stuff. So, algae comes in and consumes on the excess.

 

[brutus]

try cutting back your lights from 14 or 15 hrs to around 10 or 12 max on a timer if you have one.

 

[fort384]

What kind of co2 levels are you getting? My guess would be too much light, not enough co2, and lack of a macro nutrient.

 

[mackdaddy81]

Here is a link to the iron supplememnt I am using. It has some other stuff in it, but it is mainly iron.

Hagen Plant Gro - Live Plant Care - Fish - PetSmart



As for the CO2, I checked my KH and Ph and compared it on one of those CO2 charts and it said I was getting anywhere from 15 to 20 ppm.


I don't have a timer, but I will definately start reducing the light time.


How do I find out which nutrient is out of wack, and when I find out, how do I correct it?

Thanks for the fast replies!

 

[fort384]

yeah, you are close on the CO2, but you really want to consistently stay about 25-30 ppm to help you curb any kind of algae growth. You could add another bottle to your DIY system, or decrease the interval between mixture changes.

As far as ferts, there a few different methods.

First off, you need to have the correct fertilizers on hand. Chelated iron is important, but you also need to be worried about your macroelements... Nitrogen, Phosphorus, and Potassium. These are available in several different forms. The most economical is to buy dry ferts, and mix your own solutions. However, I am currently using the flourish line of N, P, and K (three separate bottles of fert). On top of that, I use another fert called leafzone, which contains Fe and more K. I also use a comprehensive formula from flourish that contains the essential trace elements. Now, how much do you add? Well there are a few methods for this as well. One popular method is the estimative index, or EI method. This basically involves adding more than required to the tank, and then doing a large (50% or more) water change at the end of the week to sort of reset the clock, and the process starts over. Search for Estimative Index in google or on the forum, and you will find a plethora of information on this method.

The method I use, is basically I test for N and P, and aim for specific levels. K (potassium) I just add rather liberally, as it is hard to reach a lethal level of K. I then watch for defficiencies in my plants, and adjust the dosing regiment accordingly. There are several places to find "symptoms" for defficienies of various elements. I don't thinkthe dosing has to be an exact science, as long as you don't add lethal levels of any 1 solution, or allow any 1 macro to bottom out. The periodic testing (usually weekly or so) just kind of keeps me on track... I may add some extra N here, or P there just to keep levels as close to my targets as possible based on the tests.

With this method, I generally dose everything about twice a week, and just perform regular 10-15% water changes on a weekly basis. Seems easier than the EI method to me, but I am not speaking from experience, as I have never attempted EI. The prospect of a 50% water change every week for my setup seems daunting.

OH yes, I and I would strongly recommend a timer for your lighting. Establishing a strict photoperiod for your tank will make it healthier for fish and plants. You can get 1 for cheap at radioshack or online.

 

[mackdaddy81]

What are good levels of N and P? Does the excess algae come from an excess of both of these, one of these, or not enough of one or both? when I test I want to know what should be corrected to fix the problem. Also, what kit do I get to test for P? I assume that I test for N with a nitrate test kit, but I can't find any test kit for P at Petco and Petsmart.

 

[fort384]

Yeah you really need to go to a specialty lfs or order online to find a good P test kit. Algae will grow in an imbalance of any of the nutrients. I think the bigger problems arise when you bottom out on 1 of the macros, as opposed to having excess, so long as there is some N P or K available for the plants to utilize. I aim for 15-20 ppm N, and .5-1 ppm P. I don't test for K, I just make sure I add enough (more than enough) to keep K deficiencies at bay. I will say in my tank, I experienced far more algae when I tried to keep the levels low, as opposed to making sure there was more than enough available for my plants. My tank is heavily planted, so it soaks up nutrients quick. I can tell you that when I tried to keep Nitrates at 5-10 ppm, I had some BBA issues. At the advice of Purrbox, in my estimation a fw plant genius, I bumped the levels up to 15-20, and it was like night and day, the difference it made for the health of my plants/tank.

I use a Salifert PO4 test kit which seems to work for me. For Nitrates I use an Aquarium Pharmacueticals test kit.

 

[mackdaddy81]

I just got a phosphate test kit and it said my phosphate level was between 0 and .25 ppm. I went and got my nitrate tested at the pet store and they told me that it was about 0, maybe a little more. Does this mean that I don't have enough nutrients? Also, how do I mix my own dry ferts and where can I get the stuff to do it? And how do I know if I have enough K?


Thanks!

 

[Purrbox]

You'll want to bump your Nitrate levels to about 20ppm. There isn't an inexpensive and accurate Potassium test kit, but luckily Potassium is nearly impossible to overdose. You best bet is to simply dose 20ppm each week and adjust if needed.

Rex Grigg carries dry ferts as does Planted Aquarium Fertilizer.

 

[fort384]

I think u could bump your p up a bit too just to make sure you dont bottom out midway through your dosing regiment.

 

[mackdaddy81]

So I think I am going to make my own fertilizer, and I looked up these recipes online. Let me know what one you guys think is better, and if you have any tips or other better recipes I would love to hear them.

Thanks!

References - Control of Algae in Planted Aquaria

Macro Nutrient Aquarium Plant Fertilizer DIY Recipe