API vs LFS Nitrate tests

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el_jeffe

Aquarium Advice Newbie
Joined
Jul 2, 2017
Messages
8
Location
Austin, TX
Hi everyone - sorry for the long post I just want to make sure I provide as much info as possible as I'm still a beginner. Thanks in advance! :D

My LFS tested my water and said I only have trace Nitrates however my API liquid test kit (I shook the bottles for like 3 minutes) shows 40ppm and the API test strips show 40ppm if I let it sit a minute or 2. They mentioned that the API test kits were sometimes inaccurate. They suggested I dose some nitrogen for the plants but I’m really nervous about adding nitrogen. I plan on getting slowly more high tech with the plants and fertilizers but I don’t want to do too many things at once. Just want to make sure the tank is stable for the fish first. Should I buy a different brand test kit to see what I get? I plan on doing a 50% water change tonight to bring the Nitrates down if they are in fact that high.

API liquid tests:

0 ppm ammonia
0 ppm nitrite
40 ppm nitrate

API test strips:
40ppm nitrate if the strip sets for more than a minute but at their 30 seconds according to the directions <20

LFS test (I think they’re using Fluval or Hagen liquid)

0ppm ammonia
0ppm nitrite
Trace nitrate - they didn’t give a number but said it was lowest on their scale


History:

Did a complete tear down of the tank (except the filter) 1.5 weeks ago and changed substrate to eco complete. I have 8 different live plants and a moss ball. Since I didn’t’ change the canister filter I figured I had a good amount of BB left and only did a 10% water change a few days ago. I did add purigen to clear up the tank from the cloudiness of the new substrate.

Equipment:
29 Gallon Freshwater
Eco complete substrate
Marineland 160 canister
Fluval 3.0 plant LED
Fluval co2 canister
UV sterilizer(I use this since I give the fish away I want to avoid sickness)


Stock:
2 Amano shrimp
1 assassin snail
18-20 juvenile platys (I have a guy that picks them up every time they breed so they’ll be gone tomorrow)
 
Hi, have you tested the api ones on say tap or bottled water where should be no or very little nitrates? That should check if api is on trend at least.
 
Generally I’d expect to be within say 10 or 20ppm (ie similar’ish). I haven’t tested vs Hagen or Fluval (this was versus $200 farm kits).

They’re never going to be great but I’ve found pretty much no issues for tracking trends for their price.

Old kits, expired, maybe very high nitrite or salt, cap left off in hot weather, not well shaken - these have caused issues.
 
Last edited:
I did test my tap water and it showed 0 nitrates so I guess it's picking up something. I tried a few more API test strips and they're now saying trace nitrates like the LFS but the API liquid is still 80 ppm so I think something is wrong with it. I don't want to waste the other tests in the API kit since it seems accurate but I am going to pick up an alternate nitrates test just to verify. Anyone ever tried the Seachem or Fluval? I have a Seachem iron test kit and I like the sliding color chart.
 
I’ve got that one as well. From memory seachem often have reference standards so if the case, could be handy for you where getting differing results from test kits.
 
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