branfrog

I did a 'fishless cycle' on our new 20 gallon tank planning for a planted tank. To start we purchased 5 plants: Water Sprite, 2 Cryptocorynes, Micro Sword, Chain Sword and added them on day 2. Through the use of ammonia, Hagen Cycle and the plants we saw the nitrites spike beyond measure then slowly disappear to 0 ppm over the course of 25 days. Slightly earlier than I thought, 5 days later we added our fish stock and all is well!

Fish are happy, plants seem to be thriving using Excel Potassium, Flourish and a co2 injector. All plants are showing new growth, the chain sword sprouted a total of 7 new individual plants and we bought new plants, (in all we have about 20 individual plants now).

I was never able to detect above 0ppm of nitrates, even as the nitrites were declining during cycling; I always attributed this to the plants consuming the nitrates as it was produced. But now that I stocked my tank with fish to capacity, (using the 1" of fully grown fish to 1 gallon rule), my nitrate tests still result in 0ppm, (my neons are not fully grown yet, but they are close).

My question is: is it bad in a planted tank to not be able to detect nitrates? I read on the internet that nitrates should be about 10 ppm in a planted tank? I had brown alage that my ottos are keeping in check, however it seems Red Brush algae is pretty proliferant in my tank.

My aquarium's chemistry:
Ammonia 0ppm
Nitrites 0ppm
Nitrates 0ppm
Ph 7.4
dKh 3
GH 8
Phosphates .5ppm

Any input will help! Thanks!

Jay

Plants need N03, preferably always available during the lights on period. It is suspicious that you are measuring 0 N03 in a cycled tank with fish. I would get a second opinion perhaps from the lfs, or a new test kit. It is highly unlikely that you do not have some N03 present. You may need to find a source of NO3 and add it to your fert routine to keep the ppm consistent.

For a moderately planted tank, with moderate light 2 - 2.25 watts per gallon 10 ppm of N03 consistently available is probably going to be ok. I keep my NO3 in the 25+ ppm range.

I would also raise my PO4 to at least 1 ppm

Based on your paramaters your CO2 level is at the 4 ppm level. That is not enough gas to do you much good. You should probably be in the 20 ppm range during lights on.

The red brush algae (assuming a correct identification) also called black beard algae, is not good news. This stuff will wipe out your plants. In a planted tank, inconsistent or insufficient CO2 combined with insufficient P04 will trigger the growth of this algae. Raising the CO2 and PO4 will significantly slow it down and it will gradually die off. The fact that your N03 seems to be low does not help either.

Regards,
Jay

branfrog

Thanks for the information!

I actually have an excess of light with a 65W on my 20 gallon: 3.25 w/gal not accounting for the space the substrate is taking up. It?s a satellite fixture with a 65W Sunpaq lamp and a LED lunar light. Hopefully the excess wattage is not detrimental, typically its on for 7 hours a day.


I'm thinking it is Black Beard/Red Brush Algae, its brownish-red and clumps together on my small leafed plants, (i.e. water sprite). I usually shake some, (but not all), loose and scoop it out with a net everyday. Im going to ramp up my Po4, Co2 and No3 as you suggested as that red brush algae is also an eye sore.


I looked again at my color card for my nitrate test kit, for some reason I was thinking the color tone above 0ppm was .25ppm, but its not, the next value measured is 5ppm, so indeed my test is too 'macro' to detect the low levels of No3.


I searched and found conflicting reports of Potassium Nitrate sources to increase an aquarium's No3. Have you heard of "Green Light Stump Remover" available at Ace Hardware? It's supposed to be pure KNO3, but some say there seems to be added gunk.

Jay, what do you use to increase nitrates in your tank?

Jay

I buy all of my ferts dry, usually at the agriculture grade, and mix stock solutions so I know exactly how much to dose to reach a target ppm.

I use potassium nitrate KNO3 for my NO3, and Potassium mono phosphate
KH2PO4 for my PO4 and I get the benefit of enough Potassium from the combined K content of each.

www.AquariumFertilizer.com is a great place to buy dry ferts.

The Stump Remover will work but is is a lesser grade and a much larger grain witch takes a long time to dissolve.

That is a lot of light, you definitely need to get your CO2 and Fert routine established or you will be constantly fighting algae attacks.

Jay

branfrog

Awesome! That website is just the ticket I needed. Until now, all I could find was the cheap DIY sources, or the way too expensive Laboratory chemical grade stuff. I do need to get my parameters in check, that black beard algae has increased by about 30% overnight.


Thanks again Jay!


For anyone else following this thread, its good to note that chemicals such as potassium nitrate should be proportioned correctly for your tank size, and added gradually over a period of time before establishing your optimal level, otherwise it could be lethal to your fish.

I pulled up this table from a Google search concerning potassium nitrate:

Mixing 2 tablespoons of KNO3 into 250ml of water will give the following approximate values.

10 gallon : 1 ml of above solution adds 2.16 ppm NO3
20g : 1 ml of above solution adds 1.08 ppm NO3
30g : 1 ml of above solution adds 0.72 ppm NO3
40g : 1 ml of above solution adds 0.54 ppm NO3
55g : 1 ml of above solution adds 0.39 ppm NO3
75g : 1 ml of above solution adds 0.29 ppm NO3

Raise the NO3 by 1ppm a day until you reach your desired level.

Jay

I could not agree more! This is not a lets throw some in and see what happens process!

branfrog... you should be able to reach Chuck's page from that website, he has a great calculator for figuring ml added for ppm targeted. IMO I do not agree with his target levels, but the calculator is great.

Jay

branfrog

Jay, I got a question for ya if you have a moment...

I'm still trying to correct the chemistry in my nitrate deficient tank. I received my dry potassium nitrate about 2 weeks ago and have been slowly adding the dry fert/water solution per 'Chuck's calculator'.

I first thought that adding potassium nitrate would have a cumulative effect on nitrate levels. I added 1 ml of solution into my 20-gallon tank per day for the first week hoping to have a target of approx 7-8ppm nitrates by the end of the week. But instead it tested at near 0 again, it seems the plants are consuming the nitrates as it is added.

Last week, I began to increase the daily dosage of potassium nitrate with 2ml on the first day, then increasing to a daily addition of 4ml, 6ml and eventually 8ml at the end of the second week. However even with the 8ml potassium nitrate when I test nitrate levels, (4 hours later), it still reads near 0.

I mixed the dry ferts with water to the correct proportions, so I can only assume I am raising the nitrogen levels per Chuck's calculator at the instant of dosing.

In your experience do plants consume this much nitrates?

Thanks to fishtankforums.com, I know my eventual nitrate target is 20 ppm, however at this rate, I will soon be adding enough potassium nitrate to increase levels from 1 to 10ppm in the morning then the plants will take it back to 1 by evening. I was trying to introduce the nitrates slowly so as not to harm my tetras, however I?m concerned when I get to the 20ppm level the swings will be too much for the fish. Again, this is a moderately planted tank, not heavy.

How much of the potassium nitrate solution do you add to your tank to maintain this 20ppm level?

Iam also adding mono potassium phosphate, but the phosphate levels seem to be cumulative and are holding at 2ppm without additional ferts, only added at weekly water changes.

Thanks in advance!

Jay

Well, good news on the phosphates.

You are starting to sound like a planted tank guy

You are correct, the plants do not consume that much NO3. Have you checked your test kit? Are you using any chemicals that would adsorb NO3? Sometimes I need my wife to look at a color for me.

The reality check here is that if you are mixing your stock solution correctly, then you ARE adding X amount of NO3. I rarely test anymore

What I do is fix my target....say 30 ppm, this is the amount I want to reach at the end of the week. I divide that in thirds (10 ppm) and dose three times a week, every other day. I combine the KNO3 and KH2PO4 dose one day and the micro nutrients (flourish) on the other day. That leaves you one day off with no dosing. Water change minimum of 50% on day 7 to reset the tank.

IMO a 20ppm target is not going to mess with your fish as long as you do the routine water changes.

Jay

branfrog

Well, I gave a lot of thought today Jay's post and realized that something was seriously screwy with my nitrogen. I decided as a last effort to add 10ml of potassium nitrate solution to my tank at once then take a nitrate test 20 minutes later, unsurprisingly the test still showed 0ppm.

Either something was either wrong with the test, the dry ferts, or my 'cut your own' HBH poly filter fabric in my canister. I decided to trust the dosing calcs rather than the API test.

Lying in bed tonight I sprung an idea to get a test baseline reading on nitrates. I jumped out of bed, got a gallon of tap water and calculated what it would take to raise it to 20ppm nitrates, test it; then 40 ppm and test it. These both resulted in 0ppm again! In utter confusion I went and consulted the almighty instruction manual.

Apparently I have been conducting the test incorrectly this whole time! Doh!

Up until now I have been following the instructions on the back of the color key card which has a picture of inverting the test solution 30 seconds, add 10 drops to the test tube, then invert the test tube for 1 minute. The instruction manual clearly states to "shake vigorously" otherwise the accuracy of the test will be compromised. I retested in the correct manner: test gallon of water: 40ppm on the nose; then tested the aquarium: 20ppm on the nose.

So here's to reading instruction manuals!

I calculated it would take me 22 days to raise my nitrates to 20ppm, but with all the extra dosing, here I am on day 10 at my target level. Yay! If not anything else this was a great learning experience in ferts and planted aquariums and I was given valuable input on my co2, potassium and phosphates. Thanks Jay!

One last thing, in this statement about trace minerals are you referring to Flourish 'Excel' or the Equilibrium product.

Jay

I won't go there on the test thing

I dose NO3 and PO4 on the same day three times a week (1/3 of my target for the week) a 50% water change is essential once a week to reset the tank.

I dose Seachem Flourish (trace nutrients) on opposite days.

Excel is a carbon source.

Equilibrium is a GH booster.

I use all three. You can get a cheaper, just as good, GH booster from the fert site.

Jay