CA/SA nitrate monitoring and water changes

[seedubs1]

So I've recently set up a new tank. It's fully cycled, and running well. All fish are healthy and eating well.

Tank (100 gal) has been set up running with fish in it (1X 3.5" GT, 4X spotted pictus, 3X giant danios, and 2X black skirt tetras) for about 1 month now.

I have been monitoring ammonia, nitrate, and nitrites with the api freshwater master test kit, and they have ALL been 0 for the past 3 weeks.

I've got quite a bit of green algae growing on the background/decor. I'm figuring this is what's using the nitrate as food, and that's why I'm not registering any nitrate. It's not harmful to fish, and I like it on the background, so I'm not going to remove it. It's seeming to keep my nitrates 0 as an added benifit (correct me if I'm wrong).

So question is.....When and how much percentage water do I change? Normally, I do whatever percent change however frequently I find I need to keep nitrate stable at or under 20 ppm (for example 50% one time per week for my JD to keep nitrates at or under 20 ppm).....But no nitrates have been present in 3 weeks after the tank was done cycling.

Anyone have any input?

 

[Aqualoon]

Just do enough to gravel vac the substrate and monitor the nitrates weekly to adjust as needed.

I'm in the same state, my tank generates less then 5ppm of nitrates in a week so I just do enough of a WC to get the poop off the sand.

 

[VRWC]

Id do a 50% change once a week no matter what the levels are.

Removing nitrates arent the only reason you are doing water changes.

Pheremones can build up as well as other chemicals and keep in mind everything in the tank that you arent checking for also alters the chemistry of the water.

Also, dirty water supposedly holds less oxygen.

Im no expert on the tank cycle or chemistry, but I do know that since I went to 50% water changes weekly about 5 or 6 years ago, I havent had a SINGLE problem with any of my tanks unless I added a fish without quarantining him first.

 

[seedubs1]

Yeah, that's the main thing I'm worried about. I know there are other chemicals that we don't test for that could be building up.

So I think the plan will be to start this week with a 25% w/c. And do one w/c weekly moving up slowly to a 50% w/c over the course of a month or two. (not just jumping strait into the 50% w/c because this will be the first w/c on the cycled tank, and I've found that starting at 25% or so and slowly moving up to a weekly 50% w/c works best for me as it seems to disturb the newly formed BB the least)

 

[Aqualoon]

BB doesn't live in the water column, this is why it doesn't do any good to transfer just the water from one aquarium to 'jump start' another. Your BB lives in your filter media and on your decor/substrate.

I personally don't do 50% water changes because my city water isn't the greatest (they add chloramine and chlorine - I add Prime of course prior to adding new water) and there just isn't a need.

 

[flowerpower]

That sounds like a good plan.

 

[cichlidfish]

I kind of have the same problem, but my nitrate is around 5-10. I have a 72g that is over stocked w/ a sand substrait, and live plants. I am doing 50% water changes 2-3 times a week, and cleaning out the filter once a week. I have been having a difficult time w/ algae growing on my plants and it actually has killed some of my hornwort. I am constantly testing my water.

 

[seedubs1]

@ aqualoon

I know the BB reside on surfaces and not in the water column.....Hence pot scrubbers with a high surface area in my wet dry.

The reason I gradually increase to 50% w/c is because when the BB is still so new, I think that slight disturbances in environment (changing large percentages of water) can disrupt the colony and be a slight set back.

This may, however, be completely unfounded, but I base this theory on what SOME people who do fishless cycling have seen when they do their final "large percentage" w/c right before adding their fish. They find that the disruptance in environment kills off a good portion of the new BB colony and they start another small scale cycle when they introduce their new fish (which give off less amonia than the fishless cycle introduces, so the whole original colony should have been able to take care of the bio load created by the new fish). I believe that this is because the new colony is still too young to survive a large water change, however, once further established, larger water changes have little, if any, effect.

 

[Aquanero]

Nitrates are a good indicator as to how the tank is doing overall. However if it's not a heavily planted tank my experance has been to do a 50% water change weekly. Sometimes I do more but 50% is sufficent in most cases along with a gravel vacuming. I would check your tap water for everything your test kit is capable of one a quater as a base line because city water can change seasonally. Phosphates is another thing that increases the growth rate or presents of some types of algea.