# So I tested my water...



## AKnickolai (Nov 30, 2007)

I never wanted to test my water because of the effort involved with making decent reference solutions. Well, I caved. I've got a scale for bullet reloading that is super accurate at small weights and some graduated cylinders. I made the reference solutions per my own refresher in chemistry (verified with some google searches, because I'm not chemist) and went about testing my tank. What I found was that NO3 was around 80-100ppm and PO4 was at least 20ppm. WOW! That seems really high. Up until now I have been more or less following EI for a 20-40 gallon tank. I did many water changes over the course of three days and NO3 is now about 20-30ppm and PO4 is still in the 10ppm range. I've added no fertilizers during this time and experienced no loss of plant growth or algae. I have been doing the required 50% water change as part of EI, but perhaps was not taking enough water out? Anyway, the tank has been running awesome and only had some minor algae problems when the tank gets overfed. My question is, does anyone else who doses the water column bother monitoring nutrient levels?


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## Zapins (Jul 28, 2004)

First, you should have a look at the fertilator (top left of your screen) or here:http://www.aquaticplantcentral.com/forumapc/fertilator.php

It will do all the calculations for you.

100 and 20 seems very high (especially the phosphate reading). Unless you have additional sources of nitrates and phosphates (tap water, soil substrate?) I don't see how you could get readings like that. EI is made so if you do 50% water changes per week the maximum nutrients you should be able to get in your tank long term is 2x your dose. So if you add 15 ppm nitrate per week you'll have 30 ppm nitrate if none of it is used by the plants.

Either the calibration you did was not successful or you have additional sources of N and P - the values should not be that high otherwise.

Most people do test values but not regularly. After figuring out a dosing regimen that works most people just go with it and ignore test values.

Also, if your plants were growing well, then why change conditions?


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## AKnickolai (Nov 30, 2007)

I did use the Fertilator to check my results, it is a really cool tool. I just wanted to build my own so I can use it w/o an internet connection if need be. I ran tests on my tap water and there are no sources of nitrate or phosphate. I think what may have happened is that I upped the dose on EI a few weeks back. 40 gallons is the break point in the dosing scheme, I usually used the 20-40 recipe, but did 40-60 for two weeks to see what happened. End result, I think I just got some build up of nutrients in there. 

I'm not really looking to change anything, as the tank is doing perfect. It's just more of the fact that I like to tinker and do get some strange satisfaction out of validating theory with results. Even if it is a little time consuming and likely +/-20% or so in terms of accuracy due to the methods I have available to me. I think this tank proves you can have wild excess of nutrients and not have algae problems, which is interesting in itself. 

Are there any quick and dirty numbers for toxicity levels for the fertilizers we use or common values when fish begin to be stressed? I observed no ill behavior from any of my fish (black neon tetras, apistos, ottos, and corys).


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## Zapins (Jul 28, 2004)

Welcome to the club of tinkerers! There are quite a few people on this site that tinker and experiment.

Toxicity values are an interesting topic. I have been researching them for some time now. I am still working on consolidating all the info into a guide thread, but there are several posts in here from page 5-last page, I think I have a semi-summary page towards the end in the last 2-3 pages.

Most of the toxicity values that matter are micro nutrients. It seems that you can have fairly high macro values without toxicity issues, but fairly small micro values before you start seeing issues.

http://www.aquaticplantcentral.com/forumapc/fertilizing/88403-trouble-farm-help.html


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## AKnickolai (Nov 30, 2007)

That is a good thread, lots to digest there for sure. I did a little more playing with the nutrient calcs and have one more question. My tank has spent at least 3 weeks in high NPK concentrations and doing awesome. Why not just simplify the dosing schedule and hit the tank once per week to put it in the upper range of NPK and call it good, seems easier than measuring out the same thing in smaller doses for daily delivery.


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## Diana K (Dec 20, 2007)

I could see readings that high if you are also overfeeding the fish. 

Try a week or two of greatly reduced feeding. Feed only half as much and only half as often (1/4 of the normal food)
For example, if you normally feed a teaspoon AM and PM, then go down to .5 tsp AM only. 

If that does not correct the problem (or the fish start eating each other) then adjust the EI dosing. I had to do that for my more heavily stocked tanks. 

Fish food contains a reasonable amount of N, P and most traces. It does not contain much K, Ca or Fe. 
If your NO3 stays up there where you want it with just fish food, then probably the P and traces are also pretty good.


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