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RO water

Posted: Mon Jan 06, 2020 10:56 pm
by Baardman
Hi guys hope everyone is doing well in the new year. I have been having issues of eggs hatching prematurely and was suggested by a friend that I drop my ph. So im going to start doing water changes with RO water is it needed to remineralize it before adding it?

Re: RO water

Posted: Tue Jan 07, 2020 12:38 am
by Lycosid
Baardman wrote:
Mon Jan 06, 2020 10:56 pm
Hi guys hope everyone is doing well in the new year. I have been having issues of eggs hatching prematurely and was suggested by a friend that I drop my ph. So im going to start doing water changes with RO water is it needed to remineralize it before adding it?
So normally RO drops the pH because it lowers buffering capacity and so other things (like bogwood) leach weak acids that drop the pH in the absence of any buffering ability. Using RO to drop the pH is sort of indirect. You will definitely drop hardness if you don't remineralize, but you might also prevent the pH drop by remineralizing.

Re: RO water

Posted: Tue Jan 07, 2020 1:08 am
by Baardman
Im very scared of Ph swings

Re: RO water

Posted: Tue Jan 07, 2020 8:05 am
by Bas Pels
What is it you want to reach? I think a softening of the water. As stated above, this lowers the buffering capacity and will thus enable a lower pH.

Apparently, now your water is too hard, and therefore you would want to change water with pure RO water. However, do take time to airate it.

After a while - depending on how much and how often you change water, the GH will drop to unsave values, and I would certainly remineralize to GH = 3.

It is not that hard to calculate the value - in case you change 10 %, the hardness will be reduced by this 10 %, going 8 - 7.2 - 6.5 - 5.9 - 5.3 and so on.

if you change 50 % it will be 8 - 4 - 2 and than you better remineralise.

the pH should best drop because of the availability of peat, or old leaves or such

Re: RO water

Posted: Tue Jan 07, 2020 10:42 am
by dw1305
Hi all,
Baardman wrote:
Tue Jan 07, 2020 1:08 am
Im very scared of Ph swings
You definitely will get pH swings, but you don't need to be scared of them.

As your water gets softer, and you move towards pure H2O, pH inherently becomes more and more unstable. This happens both in nature and in the tank in soft water.

The problem is that pH isn't a linear scale, it is both a log^10 scale and a ratio. I think pH is just conceptually difficult. I find it's easier if you try and think about changes in pH in terms of changes in water chemistry. I try and avoid large changes in water chemistry.

In hard water you need a large change in water chemistry to cause any change in pH,
in soft water small changes in water chemistry cause large changes in pH.

I'd cut your RO with a little bit of tap water to give some dGH/dKH and I would add Alder (Alnus spp.) "cones" or Indian Almond leaves (Terminalia catappa) etc. as a source of humic compounds (https://tanninaquatics.com/blogs/the-ti ... -aquariums).

In soft water I use a conductivity meter to give me an idea of base status, it isn't ideal, but it is a lot more straight forward than using a pH meter. I'd aim for about 100 microS.

cheers Darrel

Re: RO water

Posted: Tue Jan 07, 2020 2:21 pm
by Bas Pels
Point is, in nature the waters are Always much, much bigger than our tanks. I got a 4 meter / 13 feet tank, which is quite large, but a little creek is still much, much bigger.

pH changes further travel very fast trough wate,r much faster than anything, apart from sound and light. That is, the large size of natural waters will ease any pH crash, which in a tank still can happen.

But what will cause such a pH crash? Rotting organic stuff, that is too much food, a dead fish or so. If you keep your tank free of this, you will have eliminated some 90 % of all pH crashes.

Re: RO water

Posted: Tue Jan 07, 2020 4:07 pm
by Baardman
After the 90 days of January ill oreder a ph pen and a tds pen to see exacly where im at i find color strips just frustrating i need to get down to 5,8 to 6

Re: RO water

Posted: Wed Jan 08, 2020 11:16 pm
by TwoTankAmin
I do ro/di. I would caution your re a pH pen. I do not know about the lab field quality ones, but the more inexpensive ones are crap imo. I burned through two very fast. Instead, I now use a continuous monitor that reads conductivity/TDS, Temp inf F or C and pH. This works great and only needs the pH recalibrated about every six weeks.

I have a couple of TDS pens and they work great and were inexpensive. I have yet to recalibrate them after several years.

Re: RO water

Posted: Thu Jan 09, 2020 4:10 pm
by Jools
Going back to the first post, can you tell us more about the eggs that hatch prematurely. This is kind of new to me?

Jools

Re: RO water

Posted: Thu Jan 09, 2020 6:28 pm
by Baardman
well the species is Dekeyseria brachyura incubation time is close to 10 days mine hatch around day 4 to 5. my temperature is around 26 degrees Celsius ph 6,8. my friend that keeps them in Australia is having the same issue of them hatching premature only thing we have in commen is the higher ph. I have had loads of discussions wit Lars on the subject he was the one who suggested i lower my ph

Re: RO water

Posted: Thu Jan 09, 2020 7:23 pm
by Jools
pH 6.8 is a little high for the species but it seems a fine margin to have that big an effect. Anyway, Lars has bred more plecos than me, so I can't say it's a bad idea - just not heard that before (in plecos) hence my curiosity.

So, you can't go much better than Darrel's advice, I know it's summer for you, but if you have an opportunity to collect rainwater that might also be useful.

Cheers,

Jools

Re: RO water

Posted: Thu Jan 09, 2020 9:06 pm
by Baardman
i do manage to nurse a couple of fry to survive im hoping that once they are big enough to spawn that they will do better in my water than the wild caught ones