dosing using dry compounds

[motoman]

Hey guys I did some research on fertilizers and then took the readings in my tank and found that my nitrates are 0 which is not good for growing plants which I'd like to do. So I took a trip down to B & B Hydroponics and the guy there was very knowledgeble (don't know his name but he's a stocky guy with a shaved head and is really smart) but now I'm wondering about mixing up my solutions. I have a mixture for my KH2P04 where by mixing 5 tsp of the dry compound to 250 ml of water will give me 0.88ppm of phosphates per ml so that's fine. My real question concerns my Nitrates solution. Just wondering if anyone know how much CaN03 or MgN03 I should mix into 250 ml and how many ppm/ml I'll be getting with that solution. Any tips would be great. I used Chuck Gadd nutrient calculator to come up with my potassium phosphate solution but he didn't list any for MgN03 or CaN03. Any help would be great.

[BigDaddy]

For dosing nitrate (which some planted tanks don't need [i.e. low to medium low light tanks]), just about everyone uses KNO3, not CaNO3 or MgNO3.

I don't know too many people who use Calcium Nitrate or Magnesium Nitrate... simply because most people already have plenty of calcium and magnesium in their local water.  Plus, you are more likely to have a K deffeciency before you have a Ca or Mg deffeciency.

PS - Unless you have high light, I wouldn't be tampering with dosing phosphate.  Even then, my 75 gallon tank only gets a dosage that brings the total volume of water in the tank up to .35ppm of P.

Using your 5 tsp to 250mls giving you .88pm of P, I'm assuming you have a 20 gallon tank.  Unless you have well over 70 watts of light over that tank, I wouldn't dose .88pm of P straight.  In fact, I wouldn't dose P at all until you have N and CO2 under control first, as those two being out of whack will be your main cause of algae, not P.

If you do not have a high light tank, then dosing P is a waste.

[motoman]

I'm not too concerned with dosing Phosphates since there is usually plenty of it from fish food etc. I just picked up some since it was only $2.00 which is what I paid for the other compounds as well. They didn't have any potassium nitrate at the time so I though I would try the Mg and CaNo3 compounds. I do have high light over my 10 and 20 gal. currently 5+ wpg. I'm using R/O water so it shouldn't have high levels of anything to start with. I'm not sure what levels of Mg or Ca would be present after adding R/O right. I'm going to pick up some KNO3 this week or next which is what I was looking for in the first place. The compounds are really cheap and since I'm looking to get a much bigger tank sometime this year (55 + gal) I thought I'd start asking questions now and playing a bit to get a feel for dosing and getting my plants growing well.
I would not be dosing the P as a one shot dose. That would be a very bad idea. I was thinking that once things are rolling well if I need to add P then I will add it 0.1 ml at a time until I achieve the proper levels for all my compounds. As mentioned before and by you Phosphates usually aren't something you want to just start adding or I'll have another outbreak.
All this aside if/when you make up a KNO3 solution, are you premixing it with water and then adding it or do you add it dry and how much? Thanks for the advice.

[motoman]

Did some more research and you are right most people don't us CaNo3 or MgNo3 since it is in our water already and basically if you have any Gh readings you probably have enough already. So with that in mind I'm thinking that I'll be Ok to just dose using KNO3, Kent Traces and Flourish for now. When things really get cooking if I notice my PHO4 low then I can dose a very small amount of that. I'm going to make a solution using the CaNO3 this week and dose with that until I can get some KNO3 to replace it. I'm not sure what my Fe levels are but I may try out one of the iron supplements that are available at Big Al's. Any suggestions for Fe supplements if I need to add it?

[dpatte]

if i could only remember by high school chemistry (hmm  moles - and atomic weight - what was that all about?) i could work out your numbers. does anyone have the formulas for KNo3?

[BigDaddy]

If you have 5 WPG, your two biggest concerns are N and CO2, in that order.

You should be maintaining at least 5ppm of nitrate in the tank, and during lights on your CO2 MUST be at 15-25ppm concentration levels.

Getting the N to proper levels will be relatively straightforward.  CO2 will be more work, so ensure you have that down perfect.

CaNO3 is 68.1 percent NO3.  So, 1 gram of this solution in 10 gallons of water equals:

1 gram any compound in 10 gallons water = 26.4ppm

of that 26.4ppm, we want to know how much NO3 we get, which is .681 of the complete compound

So

26.4 x .681 = 17.9784 ppm per 10 gallons of water.

If you don't have a way to measure in grams, then generally speaking, a 1/4 tsp of most compounds averages around 1.5 grams.

If my math is off, please correct me.  I went over it a couple of times, but I still haven't had my required 6 cups of coffee yet!

[motoman]

Ok, thanks a lot! That helps me quite a bit. I know that I have a low Nitrate count already which is why I got some CaNO3 and MgNO3 so now I can mix up a solution and bring up my nitrate level to where it should be. My C02 is going very well and I have levels in both tanks of about 20ppm so that is good. I'll add some nitrate slowly and work on getting things balanced out and I should see some good growth in a couple of weeks. I was thinking of premixing all my compounds before and then dosing with the solution. So based on what you've just said I could mix 1/4 tsp or 1 gram of CaNO3 with some water in a container (I'm thinking of using a small bottle that Cycle was in before) and then add it a bit at a time to bring up my nitrate level  to where it should be. Should I worry about adding it in small quantities or would it be OK to just make the solution and add it all at once? Would that be too much of a shock for Tetras and Amano shrimp?
Thanks again for the help everyone.

[motoman]

Another thought here and my math may be off here so correct me if I'm right. I haven't done this in a long time.

If we have 17.97ppm in 10 gal of water and I would like to make a mixture using 250ml of water..... I need to do some converting here.
1.797ppm in 1 gallon of water
250 ml = 0.065 gallons  so if I multiply that by 1.797ppm I get 0.1168ppm per 250 ml
wait that's all wrong. That only works if I mix the 10 gallon concentration first and then just take out 250ml which is no good.
Ok so I we have a concentration of 17.97ppm/10 gal then we'd have to multiply that by 10 if we put the same amount of CaNo3 in 1 gal of H20 right? Which would give me a solution that would be 179.7ppm/gal. then I'd have to multiply that by 15.2 since we can get 15.2 250ml bottles in to 1 gallon of water. Wow that is really high concetration. Ok scrap that idea I know what I'll do. This is getting silly. Ignore that. I was trying to figure out how many mL of solution to add but it's getting crazy trying to do that. I'll figure out an easier way to get the solution I want and dose to the proper levels. I feel like an idiot trying to get this all figured out mathematicaly when I'm so out of practice. Somebody stop me!!! :shock:

[BigDaddy]

For nitrate, it's usually easier to just dry dose.

I dose P and traces in solution, N and K I dry dose.

[Nelson]

....and I've been thinking of a planting a tank!!!!   All this dialogue is sure making me reconsider!!!

[dpatte]

lol - i  just use kent blue

[motoman]

yeah I'm beginning to see why. So the change in nitrates shouldn't harm my fish and shimp assuming I only add 1/4 tsp per 10 gal of H20? Thanks a lot for all the help folks.

Having a planted tank isn't too difficult. The more you get into it the more technical it can become though. Don't let my trials and questions discourage you Nelson. It's only as complicated as you make it.

[Nelson]

yeah I'm beginning to see why. So the change in nitrates shouldn't harm my fish and shimp assuming I only add 1/4 tsp per 10 gal of H20? Thanks a lot for all the help folks.

Having a planted tank isn't too difficult. The more you get into it the more technical it can become though. Don't let my trials and questions discourage you Nelson. It's only as complicated as you make it.

Thanks for the words of encouragement.  Like the fish themselves, I'm simply taken by the beauty of aquarium wildlife and not in propagating either the fish or plants.  I take great care to keep my fish healthy but when they pass on...I replace them.  I'll adopt the same phylosophy with the plants that I plan on keeping.

[BigDaddy]

Thankfully, Nelson, there are online calculators for K N and P, so you don't have to do all this math.

It's just that few people use CaNO3 and MgNO3

[Nelson]

Thankfully, Nelson, there are online calculators for K N and P, so you don't have to do all this math.

It's just that few people use CaNO3 and MgNO3

Thanks BD, who needs a calculator or plant books for that matter....we fortunately have you!!!!!  :lol:

[BigDaddy]

yeah I'm beginning to see why. So the change in nitrates shouldn't harm my fish and shimp assuming I only add 1/4 tsp per 10 gal of H20? Thanks a lot for all the help folks.

Having a planted tank isn't too difficult. The more you get into it the more technical it can become though. Don't let my trials and questions discourage you Nelson. It's only as complicated as you make it.

NO!!!!

You can't go from 0 nitrate to 18ppm instantly.  You WILL harm or kill your livestock.  Even a jump from 0 to 10 might stress out sensitive fish like rams, etc....

[motoman]

Yeah I realised after thinking the numbers out again that kind of jump would be a very bad idea. What I did was mix my CaNO3 solution to a piont where each mL of solution would give me around 0.19 ppm and then I used a syringe to add a little nitrate at a time. Last night I added 6cc or mL which would be about 1.15ppm. Everyone seemed OK so I'll keep my eye on them and add a bit more tonight after I check and see what my levels are at. I know that you have to make changes slowly but I wasn't sure if Nitrates are as harmful to fish as Nitrites so that's why I asked what you guys thought? When you started to bring up your levels did you do it over several days or weeks or hours? I figure this may take a bit of time to get all the levels to where they need to be.

[BigDaddy]

Adding 5ppm of nitrates is usually a safe bet.  But anything more than that, and you risk stressing out fish.

I dose 5ppm straight on my 75 gallon 3 times a week.