Dosing regime for high nutrient tap water

Re: Dosing regime for high nutrient tap water

I did a quick run through my own calculator that can take into account existing concentrations (sorry its not releasable -- at this point )

Anyway, assuming your tests are correct, I come up with the following, dosed
3x per week ....

K2SO4 (K) 3/8 tsp
Trace CSM+B 1/6tsp --or-- TMG 5ml

You might want something to raise GH depending on what it is.

I suspect you could get away with say 1/16 tsp of KNO3 (Nitrate), and
a pinch (1/32 tsp maybe) of KH2PO4 (Phosphates) -- just to be sure you have
enough.

Having said that, my nitrate tests show much higher than they really are, so if you 20ppm is really 10ppm, then you will need maybe 1/8tsp of KNO3, and then you can drop your K2SO4 by 25%.

I will be interested in how far off I am from tom's recommendations

 

Re: Dosing regime for high nutrient tap water

I live in London (SE9) and also get a reading of 30-60ppm for my nitrates straight out of the tap. It's nice to know I'm not alone! (I don't think the nitrates vary that much, but my eyesight and testing ability does )

I dose the following using EI:

Greg's PMDD mix (as I have loads of it, I use this instead of a trace mix, and am aware I am adding a small amount of nitrates with this. If it ever runs out I'll switch to just traces.)

KH2PO4 – Monopotassium phosphates: Provides P and a little K.

K2SO4 – Potassium sulphate: Provides K.

With my weekly water change I add a dollop of Epsom Salts to give me some magnesium.

Although my tank is still establishing (I've only been dosing for about 2 months) my plants grow well with this system and my 'nitrate heavy London water'.

I hope that is of some help or reassurance

 

Re: Dosing regime for high nutrient tap water

320 is about 18 degrees and yes that is quite high. Can you get an analysis report from you city? In Toronto, you can get a free copy of last years -- don't even know how to get a current one. However, last years gave ranges too, and our nitrate comes out at 0, and Mg at 8 -- being the only numbers I remember since I was specifically interested.

If you are not mixing dry, what are you using??

 

Re: Dosing regime for high nutrient tap water

I'd been meaning to collate all my tank stats, so here we go...

Size
Water column is apprx 160l\42US gallons\35UK gallons

Lighting
3 x 25W T8 fluorescents's (30" interpet triton tubes).
So a little less than 2W per gallon

Fertilisation
DIY C02 with DIY reactor (am moving over to pressurised soon)
Dry ferts:
0.1 teaspooon of KH2PO4 = 2.1ppm : added 3 times a week
1 teaspoon of K2SO4 = 15-20ppm : added 3 times a week
5ml pmdd solution = 0.7ppm No3, 1ppm K, 0.1ppm Mn, 0.05ppm Fe : added 3 times a week
MgSO4·7H2O 3.3-5ppm (1 teaspoon) once a week

(PMDD mix = 15ml mixed in 100ml of distilled water)

Weekly Maintenance
50% water change (sometimes nearer 40% some weeks)
Pruning
Algae removal (mainly staghorn and a little bit of green string algae)

Monthly Maintenance
Cleaning of internal power filter
Replanting


My doseage amounts for potassium vary a fair bit as I sometimes add an overfilled teaspoon rather than a level one. Likewise for Mn.

I have one particluar plant (sadly I don't know the name of it) which is prone to holes in the leaves so Itried adding more potassium - no change. So now I am adding more traces. I saw a noticeable change within a few days of this! So I'll end up with more than 5ml a dose, but I don't know how much more yet.

I do quite enjoy the experimentation, I read from Tom to allow 3 weeks between changes (which I find hard!). Once I've added enough to get all my plants growing well (pretty much now!) I will probably start to experiment with adding less! lol. The ideal would be to know what is going on enough to be able to get away with less water changes.

Like you I have a fair bit of staghorn algae and am going to move over to pressurised CO2.... I did buy some siamese algae eaters last week and I have noticeably less already I also have oto's to eat my 'sludgy algae'

BTW I get all my ferts from Richard @ AquaEssentials - a real pleasure to deal with, great service and good advice as well.

 

Re: Dosing regime for high nutrient tap water

Yes, I'd agreee with that. I hope to be pressurised within a month or so. I'll post back to let you know if it makes any changes to the algae levels.

 

Re: Dosing regime for high nutrient tap water

I also come from the south east London area. I see you are adding magnesium which you need to do as having recently had problems with curling leaves, I found that there is little to no magnesium in our water. The GH seems to be made up of only Calcium. I tested my GH at 380mg/l. After adding Mg my plants picked up very quickly. Nitrates come out the tap somewhere between 20-50 and phosphates 1-2.

Now changed to using RO water and adding equilibrium plus NaHCO3 as adding MgSO4 was making the GH too high for my liking.

 

Re: Dosing regime for high nutrient tap water

I followed the same pattern of curling leaves and adding Magnesium. However I also started dosing Potassium and Phospahtes with EI at the same time so it is reassuring to hear that it was the Magnesium that did the trick.

I understand the importance of KH as a buffer with regards to CO2 addition and PH stability. That's as far my knowledge of water hardness goes... I've only been looking into the composition of tank water for a couple of months and General Hardness is something I still need to learn, I'm sure there is a thread already on this site that explains it...

 

Re: Dosing regime for high nutrient tap water

If it were me rather than using 100% ro then trying to build it back up i would use a mix of ro and tap water to get the desired hardness then maybe add a little magnesium if it is an issue.

 

Re: Dosing regime for high nutrient tap water

I did do that. I was cutting tap water with RO water, 1:3 which was giving me KH 4 and GH 7. But then adding MgSO4 was making the GH a bit higher, but also my TDS was getting real high, 400ppm+. I decided it was just as easy to add a bit of equilibrium and NaHCO3. It also gives me nice K levels and saves me having to treat for chloromines that we have round here.

 

Re: Dosing regime for high nutrient tap water

Depends on your tank size of course if you want to compare "tsp" to "ppm", but I aim for the following in ppm:

Nitrate (NO3) 20ppm
Potassium (K) 30ppm
Phosphate (PO4) 4ppm (that is high, I suspect 3ppm might be better)
Magnesium (Mg) 10ppm (my water comes in at 8)
Micros -- harder to measure -- its suggested that Iron can be used as
a benchmark -- I am using 0.50ppm of iron as a benchmark

 

Re: Dosing regime for high nutrient tap water

I just thought I'd report back that I now have no staghorn algae left.
I have a hunch that it is still growing, but much slower, and that the SAE's eat it faster than it grows.

Then a couple of days after the algae dissapeared I stopped putting CO2 into the tank.

I simply got tired of the constant monitoring of CO2 production via yeast bottles, this lack of CO2 is only temporarily while I slowly but surely obtain parts for my pressurised system.