Water changes in non EI tanks

[JoeBanks]

I understand the need for water changes when using the EI, but what is the point of water changes in well controlled non-EI planted tanks?

I have a 180 gallon which I cannot use the EI for because I have no way to change 90 gallons at a time. Instead I test for every nutrient using mostly Lamotte tests once a week. I keep all nutrients in the suggested ranges. What's the benefit of doing water changes in my tank?

 

[Tom Barr]

Re: Water changes in non EI tanks

We assume that the test kit measures what is occuring in the plant.
we also assume the form of the nutrient is bioavailable, most test kits measdure total alk, total NO3, total PO4, not the bioavailable forms.

Do you measure all the needed growth parameters?

You can apoproach it this way, but my and a number of folks that are extremely observant in terms of plant health, Amano among them, suggest at least 25% weekly changes for optimum health. You can get by and do pretty well without doing water changes. But use less light and you will find it much easier to balance things. That's your choice in the trade off.

You do not have to do weekly 50% either.
25% 2x a week etc
25% a week etc

As far as why you cannot do 90 gal was not stated either.
It might because you want to use a lot of RO water and the storage is not available. A number of potential reasons pop up with this issue.

You see what you really think and give each routine some time and see what you think.
Every CO2 enriched tank I've ever owned did better with frequent water changes, as well as fish only tanks. I'm not alone with this one either.
One thing to deal with and that cleans the tank up well, removes dead plant material etc is a good thing, mulm accumulation over time is not good either.

You assume it's well controlled, but there are many things the test do not tell you. The control is also determined by the test and you testing each parameter.

Mg, Ca, NO3, Fe as proxy for all traces, PO4, K+, KH.

By the time I measure that, I've done the water change with a python or a simple hard plumbed system(this would take about 30 minutes total, some less depending on the pipe sizing for drain and refill).

I do not touch buckets except to toss pruned plant scrap into.
A python water changer is not a troublesome thing to use.
With larger tanks, making the water change process simple is a very wise and time saving feature.

Once in place, it's no longer a chore or an issue. I much prefer to work on a tank when it's 1/2 full, pruning is easier, so is cleaning, replanting, not getting nearly as wet etc. If you scape and garden significantly, over time you'll agree, Amano does the same thing.

You prune while draining and refilling.
Hoses are not hard to use and reach most any place in any home.

You can certainly extend the times you need to do water changes(I';ve gone 4-6 weeks without water changes using EI), but if you feel you can do this and don't mind the trade offs, go for it.
I've done it in the past, many have, I think it's a PITA and some luck is involved. Also, do not assume the test kits, even the good ones are always right, each kit has it's own set of errors, you need to calibrate the test kits as well if you plan on relying on them solely for the dosing routines.

You can go months with non CO2 tanks and easily a month with Excel dosing. So if that is your goal, it's much easier to hit that balance and avoid test kits, tanks still look very nice also.

Regards,
Tom Barr

 

[JoeBanks]

Re: Water changes in non EI tanks

Thanks. I didn't realize there was a difference between bioavailable an non-bioavailable nutrients.

I can't do a 50% water change because although I have a hard plumbed system, I have only cold water available, so I need to let the water sit in a holding tank in the basement until it warms up and then pump it up to the main tank. I'm using an old 54 gallon tank as a holding tank, and that's the most I can change at a time. I have yet to find a 90 gallon or higher container at a decent price.

 

[quenton]

Re: Water changes in non EI tanks

Thanks. I didn't realize there was a difference between bioavailable an non-bioavailable nutrients.

I can't do a 50% water change because although I have a hard plumbed system, I have only cold water available, so I need to let the water sit in a holding tank in the basement until it warms up and then pump it up to the main tank. I'm using an old 54 gallon tank as a holding tank, and that's the most I can change at a time. I have yet to find a 90 gallon or higher container at a decent price.

I wouldn't think it would take too much to splice in a hot-water source with a tap on it or on both for temperature adjustment? Assuming you have hot-water pipes nearby.

 

[JoeBanks]

Re: Water changes in non EI tanks

That's the problem. The hot water supply is all the way on the other side of the house. It isn't worth bringing over. I also don't want to use the hot water directly into the tank as it can raise copper levels and kill my shrimp and nerite snails.

 

[Tom Barr]

Re: Water changes in non EI tanks

Just stick with the 54 gal watere changes for now, that's fine.
Just run the EI a little lean(say 1/2 to 1/3 less) for N and P. you have the test kits and once you hit on an average range, it's unlikely you will not need to do further testing if you watch the plants well.

1/3 water change weekly is not that small really.
If thing are not in good shape, switch to 2x a week, other stick with 1/3 weekly.

The other idea, add a aquarium heater to the water change bin.
If you want a larger water holder: get those rubbermaid pond bins, they use them for ponds and holding tanks etc, they make 100 gal bins for fairly reasonable amounts.

Unless the water is pretty darn cold, colder water seems to be okay for many species. Say 54 gals is 90 F, adding the remaining 30-40 gal at 60F will leave you with a decent temp over all.

The other option is to not hard plumb the hot water line, use a hot water hose if possible to refill.

I'd not bother though. Just do 54 gal changes heat it a little and blend if you want more %, or not bother and stick with slightly leaner dosing and 1/3 water changes.

Regards,
Tom Barr