Advice on Regular water changes etc? updated

That's the one I have. Shake the bottle for at least 1 minute before adding it to the tube, hard enough so that your arm aches afterwards

Now I'm completely confused and doubting my technique. Having followed the instructions carefully (complete with aching arm!) my tap water looks like about 10ppm I think. I'd better do the tank water again.

...and here's the tank water. It does look lighter, doesn't it?

By the way and speaking of tap water, my water supplier's annual report says calcium=54 mg/l, calcium carbonate=134 mg/l. What does this mean in terms of the hardness of my water?

It is possible for your tank to have lower nitrate than your tank!
Plants soak up some nitrate and filters MAY remove nitrate if you have nitrate reducing bacteria in there. My tap water is 30ppm whereas my tank is 10ppm. I get nitrate problems if I do water changes much above 15% per week as I am adding nitrate rather than diluting it.
What this thread shows is that every tank is different!
Although I always remove the brown gunk from my filter every 4 weeks, it is possible that leaving it in place could slow down the water circulation and thus enhance the nitrate reduction ability by creating anerobic areas. So the answer as to whether it increases or reduces nitrate if you remove it could be that both are right depending on circumstances!
In my case I have a Juwel internal filter at present which is specifically designed to divert water and create a slower flow though the lower part to encourage nitrate reducing bacteria. I also use media designed for the purpose in that area so I believe nitrate is being removed that way, however, as I am also heavily planted I can't say for sure which is doing the most.

raylove said:

It is possible for your tank to have lower nitrate than your tank!
Plants soak up some nitrate and filters MAY remove nitrate if you have nitrate reducing bacteria in there. My tap water is 30ppm whereas my tank is 10ppm. I get nitrate problems if I do water changes much above 15% per week as I am adding nitrate rather than diluting it.
What this thread shows is that every tank is different!
Although I always remove the brown gunk from my filter every 4 weeks, it is possible that leaving it in place could slow down the water circulation and thus enhance the nitrate reduction ability by creating anerobic areas. So the answer as to whether it increases or reduces nitrate if you remove it could be that both are right depending on circumstances!
In my case I have a Juwel internal filter at present which is specifically designed to divert water and create a slower flow though the lower part to encourage nitrate reducing bacteria. I also use media designed for the purpose in that area so I believe nitrate is being removed that way, however, as I am also heavily planted I can't say for sure which is doing the most.

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So it's all clear as mud then!

I’m just north of the M25 and my tap water tests read:
Nitrate 10ppm
Ammonia 0.25ppm

Which means if my tank water reads the same then my plants-filter-snail-shrimp combi is spot on though even better is possible. Id still change 50% a week though as I personally wouldn’t want to live surrounded by my own pee n poo.
How some fish keepers don’t get this is beyond me.

raylove said:

It is possible for your tank to have lower nitrate than your tank!
Plants soak up some nitrate and filters MAY remove nitrate if you have nitrate reducing bacteria in there. My tap water is 30ppm whereas my tank is 10ppm. I get nitrate problems if I do water changes much above 15% per week as I am adding nitrate rather than diluting it.
What this thread shows is that every tank is different!
Although I always remove the brown gunk from my filter every 4 weeks, it is possible that leaving it in place could slow down the water circulation and thus enhance the nitrate reduction ability by creating anerobic areas. So the answer as to whether it increases or reduces nitrate if you remove it could be that both are right depending on circumstances!
In my case I have a Juwel internal filter at present which is specifically designed to divert water and create a slower flow though the lower part to encourage nitrate reducing bacteria. I also use media designed for the purpose in that area so I believe nitrate is being removed that way, however, as I am also heavily planted I can't say for sure which is doing the most.

Click to expand...

Change a tank for tap in your first line.?

ClownLurch said:

I’m just north of the M25 and my tap water tests read:
Nitrate 10ppm
Ammonia 0.25ppm

Which means if my tank water reads the same then my plants-filter-snail-shrimp combi is spot on though even better is possible. Id still change 50% a week though as I personally wouldn’t want to live surrounded by my own pee n poo.
How some fish keepers don’t get this is beyond me.

Click to expand...

I'm in a semi-rural area (just south of Gatwick) so I imagine that would mean slightly higher nitrate due to the agriculture going on around me?

That depends on where your water comes from. If the reservoir/river/ground water pumping station is in an agricultural area then fertiliser run off can cause high nitrate. But if the source is some distance from where you live the water could well not have any nitrate containing run off.

My tap water has nitrate slightly yellower than 5 ppm and my water company says 4 ppm. My tanks have zero nitrate. I have a lot of slow growing plants and frogbit floating on the surface. Floating plants are fast growing plants and not only do they remove the ammonia made by the fish so it's not turned into nitrate but they also remove the nitrate in my tap water. So yes, plants can lower the tank nitrate to below tap level.

But as ClownLurch says, just because nitrate is low it doesn't mean we don't need to do water changes. there are all sorts of other things excreted and secreted by fish which we can't measure, and they will build up between water changes.
The brown goo that builds up on the filter media is often referred to as a nitrate factory. It is decomposing fish poop, uneaten food, bits of dead plant etc which are broken down to make ammonia which the beneficial bacteria into nitrite then nitrate. It should be washed off the media regularly.

justinhill said:

my water supplier's annual report says calcium=54 mg/l, calcium carbonate=134 mg/l. What does this mean in terms of the hardness of my water?

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There are two units of measurement used in fish keeping. One is mg/l calcium carbonate (though it's called ppm) so yours is 134 ppm. This converts to 7.5 dH, (the other unit). This is softish water and is suitable for soft water fish except for those few species which must have very soft water.

ClownLurch said:

I’m just north of the M25 and my tap water tests read:
Nitrate 10ppm
Ammonia 0.25ppm

Which means if my tank water reads the same then my plants-filter-snail-shrimp combi is spot on though even better is possible. Id still change 50% a week though as I personally wouldn’t want to live surrounded by my own pee n poo.
How some fish keepers don’t get this is beyond me.

Click to expand...

I do get the theory of this, however, I've kept fish for 45 years, most live to ripe old ages, spawn regularly and grow to good sizes. My water is clear (no yellowing), I'm heavily stocked and plants grow well (since I started using CO2 at least!) In the past if I've increased water changes above 15% per week I have run into difficulties. It took me a while to work it out - I was raising nitrate levels and at over 30ppm plant growth slowed, which compounded the problem.
I conclude that those other things that build up must largely break down naturally.

A few years ago I had a population explosion of bristlenose plecs. I didn't know how many I had as they stayed hidden during the day. Eventually I had to have a clear out and took them to my LFS. When I started netting then I was astonished to fish out over 50 varying between 1 and 3 inches long, and this still left me with several. On that basis my tank had been at least 3 times maximum stocking level, largely with notoriously messy fish! It had been like this for a long time with me changing just 15% per week, clearly with no I'll effects! Not that I would recommend that extreme of course!

Different strokes for different folks.
I consider myself a novice compared to others as a "Wet Pet" keeper and "Underwater Gardener".
Water changes, are beneficial to the fish and plants. The amount depends on the size of the tank, inhabitants, plants, fertilizers, filtration, feedings, etc...
Every tank is as different as a fingerprint.
Water changes replenish essential minerals/elements and removes organic/inorganic toxins that can build up over time.
I personally choose to do a minimum of 50% weekly on all my tanks. Except when setting up a "New" tank until an established cycle.
When I have fry, youngsters they get 50% changed every 2-3 days.

You will get success stories from members stating the opposite. The debate will continue.
Just my .02.
Good Luck!