high nitrates, faulty boiler???

[cheapchickens]

Hi, I wrote a prevoius post about my tap nitrates being high. After getting on the phone to my local water supplier they informed me that the max in my area was 9ppm. I wasn't convinced not until I decided to test my cold water and my hot. Cold water was 5ppm and hot was 40 - 80 ppm. So its no wonder when I was doing water changes for my tank it didn't reduce the nitrates. I now do daily changes a couple of buckets of cold water at a time. I'm happy to continue to do this so I don't reduce the temp and shock the fish. What I wanted to know was if there is a fish keeper on here who knows about boilers and could tell me if this indicates a problem with my boiler. hope somebody can shed some light for me. Thanks.

Rich

[san-ho-zay]

Did you let the hot water cool to tank temperature? If not, I'd try that first.

[cheapchickens]

hi san ho zay, sorry when i said hot i meant tank temp 25 - 26, warmish.

[akane]

Unfortunately I don't remember the reasons why things like this happen but I was taught by another forum many years ago to absolutely never use hot water. It gets contaminated by the water heater. Always use cold and if necessary let it come to room temp or drop a heater in it to match the tank water rather than adjusting your tap water to the tank. I've never had problems adding cool water straight to my tanks. It's even triggered spawning occasionally because it mimics a cold rain and a lot of species wait out the dry hot season for the cooler wet season to spawn.

[san-ho-zay]

I think a lot depends on the type of boiler. Older style systems that use a copper tank fed from a cold water tank in the loft have more scope for contamination whereas newer on-demand boilers just heat water from a fresh cold water feed. Certainly I know lots of people use hot water and don't have problems with sensitive species including shrimp.

[cheapchickens]

the boilers about 3-4 years old its an economy 7 thing. so no storage in loft but there is a sml storage cylinder above it. presume that is the water it heats at night on the cheap for day use, but it does deliver on demand also. if i add water fom the kettle to bring the cold water up to 25c will this have any effects on parameters or Gk? thanks again
rich

[san-ho-zay]

Boiling water reduces temporary hardness (bicarbonates, a.k.a. KH). The result is the "scale" on your kettle. It doesn't affect permanent hardness (calcium and megnesium, a.k.a. general hardness or GH). If you have hard water the effect of warming some water as part as of a water change is not likely to be significant. Boiling also drives off dissolved air, which would be significant if you only used boiled water but is not going to be an issue if you mix with cold water, which is saturated with dissolved air.

In other words, using a small proportion of water from the kettle to air cold water should be OK.

I can't think why your boiler would introduce nitrates. A quick search reveals that corrosion inhibitors often contain high nitrite levels but they would only be used in a closed circuit like radiators. Are you able to persuade the boiler to give you water that's heated on demand only? If so, you could test that, which would point to your Economy 7 storage tank. Did you test your hot water for nitrite also?

[cheapchickens]

I think i can stop the boiler from heating up overnight so it gives me direct hot water. I will try that tonight. just tested for ammonia and nitrite and both are 0. So its just the nitrates. my gh is 4 so its quite soft. I think I'll go for the partial boiling water method unless my water is too soft. Thanks san ho zay.