[Chris30559]

Few questions, I have been reading quite a lot on this forum, "trying to learn how to get a great planted tank going", and i have noticed on a lot of threads, people are mentioning 50% sometimes more water changes for there routine maintenance. Currently i have been doing about 20% water change on my 55 gal about once a week, for the past 3 years. Have i not been doing enough?? my nitrate has never really gotten much above 30ppm and is pretty constant around 20-25 ppm(plants benefit from this), i have a decent amount of fish, many plants, mostly java fern, and amazon sword.

Does Co2 injection or the addition of dry fertilizers, (which i will be starting soon"K2SO4,KH2PO4, and CSM+B plantex") require a higher amount of water changed each week?? also i will not be dosing KNO3 because i think i have enough nitrate (20-25ppm) does anyone else agree with this as well??

Thanks,
Chris

 

[blackandyellow]

Not an expert here but I understand that if you fertilize using the EI method, the 50% wc at the end of the week is needed to "reset" levels, because otherwise the levels of some minerals would end up too high for the living creatures. I think basically EI supplies an overdose of some elements for the plants to have plenty, and then the system is reset at the end of the week

I dose using the seachem charts (whatever they recomend for my tank size) which is not exact science, and I change around 25% - 30% water split biweekly.

I read in TFH an article about water changes, where they compared doing many small wcs compared to one large wc, and in they concluded that in the long term the large wc was better, even though it stressed more the fish

 

[Philosophos]

The answer to all of this has to start with a mandatory, "It depends."

One large water change can be hard on some fish, but others appreciate it and head into spawning mode.

For EI methods, one 50% WC a week is the starting point, but not the limitation. At times I've done 2x 30% water changes to get the same effect. 10% 6-7x a week would be about the same as a 50% as well. In lower tech tanks with 1-1.5wpg (on average) lighting, you can get away with 50% every two weeks to month with lazy dosing.

Other methods are designed to avoid changes. PMDD and most commercial fertilizer lines meet this description.

For many of us, intense water changes go with the fish we keep as well. Sensitive species appreciate 50% water changes every week or two, and it's not that much work when you stop using buckets.

Nothing about CO2 or dry ferts in and of its self requires more frequent water changes; only the methods you decide on using.

-Philosophos

 

[Hoppy]

About the nitrates: If you are supplying reasonably high light, have good CO2, and a heavily planted tank, you will not have enough nitrates to support the plant growth without dosing nitrates, or doing big water changes with tap water that is high on nitrates. Don't trust your nitrate test kit, or any other test kit, unless you first calibrate it to find out what the "readings" really mean. No one who depends on testing results for anything important should ever use a test kit or device without first calibrating it, and recalibrating often.

 

[bradac56]

Great post Hoppy,
I'd recommend doing the big water changes while using the EI fert dosing system as most people are not as [STRIKE]crazy[/STRIKE] dedicated as Hoppy is on calibrating test kits.

- Brad