Dealing with seasonal variations of GH in public water supply where RO water is not a feasible option

[Pepere]

Following @Dennis Wong advise to hold growth variables as steady as possible to avoid transition stress has been my single greatest tool to aquatic plant success.

I am fortunate to have Tap Water that is consistent all season with 6 ppm Ca, 1 ppm Mg day in day out all year. It is consistent because the water utility adds most of the Calcium and Magnesium in it.. the source water is extremely soft. The head of the water department has told me it never gets close to their target. They continually test and adjust the feed to hit target.

It is simple enough for me to just add gypsum and epsom salt to boost it to what I want.

Helping a fellow member here who is starting a 75 gallon tank in an apartment. Ro unit is simply not an option for him in the apartment for now. schlepping bottles of RO for a 75 gallon would also be a hardship. It is a tank just for family enjoyment and not intended to be a competition tank. He will be dosing diy ferts, high light and co2.

His public water supply has an average DGH of 8 with reasonable calcium magnesium balance. But the Seasonal variation is between 4.5 DGH and 11.2 DGH…

In the situation where RO is not currently an option what would peoples responses be?

At 8 DGH steady throughout the year, I would probably just go with it.

It would be easy enough to test tap water DGH before doing a water change. It would be easy enough to create a table to alter how much to-adjust gypsum and epsom salts as tap water hardness decreases with seasonal shifts down to 4.5. But the question is for the times it hops upwards to high end of range.

One could schlepp bottles for those weeks and hope those weeks are outliers…

Or one could simply target a higher DGH all of the time in the interest of stability..

So I understand the potential issues, but not enough of what numbers matter…

Am I overthinking? I know @Dennis Wong has said the Carbonate hardness has a bigger impact on plant health than General Hardness,

Is ranging General Hardness less of a concern?

Water report indicates 3.5 DKH with no report regarding seasonal variation..

 

[Mr.Shenanagins]

I’m no expert but I think your leaning in the right direction with dGH not being the issue so much as dKH . I think the only issue with dGH is if it’s missing either the calcium or magnesium completely in that entire reading.

 

[Dennis Wong]

Could use TDS pen as proxy. Shifts from baseline TDS can then proceed to do GH specific testing. Tests with TDS pen is fast.

 

[That Guy Brian]

Could use TDS pen as proxy. Shifts from baseline TDS can then proceed to do GH specific testing. Tests with TDS pen is fast.

Is there a specific brand that is better than others? Amazon has them ranging in a pretty wide price range. I don't want junk, but don't want to throw money away for no reason, either.

I am the member that @Pepere has been very kindly helping with setting up my first aquarium. A huge thanks to him for starting this thread without me even asking. I wouldn't have been able to ask the right questions in such a manner.

As for dKH , my tap water tests at zero, despite the water report (The water plant is about 13 miles from me, if that matters). If that is indeed what I need to target more than dGH, then that would be amazing, as a bit of baking soda is a LOT lighter than a 5 gallon jug of water lol

- B

 

[Pepere]

Could use TDS pen as proxy. Shifts from baseline TDS can then proceed to do GH specific testing. Tests with TDS pen is fast.

Well it is easy enough to figure out when GH is shifting. The poignant question is whether gh stability is important enough to pursue?

And given the tap water GH can vary between 4.5 DGH and 11.2 DGH, if your only option is stabilizing at a higher DGH than optimal, would you stabilize at the 11.2 DGH, or would you stabilize at 8DGH and accede to the irritation of schlepping multiple gallons of RO water on the weeks of higher DGH?

 

[Pepere]

As for dKH , my tap water tests at zero, despite the water report (The water plant is about 13 miles from me, if that matters). If that is indeed what I need to target more than dGH, then that would be amazing, as a bit of baking soda is a LOT lighter than a 5 gallon jug of water lol

All things being equal, plants prefer lower KH. There are plants that tolerate higher KH but none that I know that do better with it…

I would limit KH to the minimum necessary for your chosen livestock.

Personally I take it further being that my plants are plant centric and I avoid livestock that require elevated KH. My tap is 2DKH and that is where I leave it…

 

[Pepere]

@Burr740 ,@GreggZ ,@Naturescapes_Rocco @Unexpected Your thoughts are always valued….

 

[Pepere]

Not meaning go leave anybody else out mind you. Just trying to recruit more thoughtful answers…

 

[Koan]

If that is indeed what I need to target more than dGH, then that would be amazing

Your Amanos should tolerate this pretty well, assuming the GH goes up and down gradually and not in giant jumps across water changes. But if you decide you want to add Neocaridina / "cherry" shrimp , you'd have to find a way to keep GH stable

 

[Unexpected]

I believe the answer is in the question. If RO and lugging is off the table, you just go with it. Like @Dennis Wong mentions, you can track with a TDS meter to verify when these shifts occur, make the additions when need too, and just ride out the higher GH periods.

 

[Pepere]

verify when these shifts occur, make the additions when need too, and just ride out the higher GH periods.

So would you target an 8DGH or maybe a 9DGH level and if it goes above for a period of time just let it until it drops back down?

Just accept some transition stress with the goal of getting it back on keel affter levels return?

 

[Kwyet]

I think the easiest solution is to just remineralize to 10 or 11 dgH year-round and get plants that are fine with that. The second easiest, if a simple portable RO unit is really not an option, is to remineralize to 8 and keep some gallon jugs of distilled water available to handle fluctuations. Just my two cents.

 

[Unexpected]

So would you target an 8DGH or maybe a 9DGH level and if it goes above for a period of time just let it until it drops back down?

Just accept some transition stress with the goal of getting it back on keel affter levels return?

That I don't know.

 

[Rob23]

I think the easiest solution is to just remineralize to 10 or 11 dgH year-round and get plants that are fine with that.

Given the outlined restrictions ruling out an RO unit, I think @Kwyet has hit the nail on the head.