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Calling folks with liquid rock...

8212 Views 33 Replies 18 Participants Last post by  travis
After being immersed in this hobby for several years, and seeing that what I see does not always jive with what I read from others, I thought I'd post this.

I'd like to have an informal, unscientific discussion here of folks with hard water - defined as kh of 8 or above.

I have no proof, other than comparing what I experience versus what I read from folks who have softer waters. But personally, I feel the following are true, at least in my tanks compared to folks who have soft waters:

--Certain plants seem to be more susceptible to stunting
--Tank doesn't like it when I try to run it lean - algae starts to show itself, and plant growth slows down considerably
--Even with good CO2, bba has a tendency to show up unless I have an sae in the tank
--EI-type dosing seems to work better than daily-type dosing
--Of course, forget about trying to grow any soft water plants like Toninas, and Eriocaulons. But, for me, I can also forget a lot of Rotalas, like macranda and some of the Ludwigias as well.

So anyone care to chime in? I'd certainly be curious to see if anyone has similar issues, or is my water uniquely different? :)

BTW, my water: kh 11; gh 13 (mostly Ca)
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I can't remember what my kh is, but it is pretty high since I live in N. Florida and use well water. I have had problems with stunting if i don't dose enough as well as the algae. I am especially having troubles in my 55g with crypts where I don't dose ferts or co2, but rather put in fert tabs. The bba is coming back but not too bad as long as I do WC. I have pressurized co2 for my 10g and 20g, and I still have bba popping up even though in the 10g it seems to be dying and growing at the same time. I can grow Ludwigia repens, but that is common in Florida. I am growing Rotala mini type 2 very well as well as indica. I haven't tried growing anything too difficult yet. I have noticed that aqua soil amazonia softens the water, but I tried amazonia 1 and it is leaching tannins into the water, while amazonia 2 does nothing to the water color. Then again the ada site says thats what amazonia 2 is for hard water, but it disintegrates too easily.

These problems probably have to deal with the excess Ca in our water and not enough other nutrients to allow the plants to uptake the excess Ca.
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These problems probably have to deal with the excess Ca in our water and not enough other nutrients to allow the plants to uptake the excess Ca.
I would agree with you. We both draw from our limestone aquifer. Do you dose Mg? I add 1/2 tsp twice a week to my 50's. It seems to help some.
Your observations are consistent with mine when I used hard water. It was very frustrating. Suprisingly, you can grow a considerable amount of plants with high KH water, generally anything that won't grow above 5dKH or so. The most difficult factor to control is CO2. It's extrordinarily difficult to get enough CO2 dissolved in the water, particularly in larger tanks. If you're using higher lighting, then forget it. CO2 misting did help quite a bit, but no matter how much CO2 I got into the water, BBA was always somewhere in the tank. I found nutrient dosing not so much of a problem, although higher levels did seem to work better than lower levels. Riding a fine line was almost impossible, whereas my tanks with pure RO are very easy to run lean.
I grew up in a small town in IL by St. Louis. It was said we have some of the hardest water in the nation, not sure how true it is. I was not into the planted tank then as I am now so I don't have measurements to give you. I can say that nothing, not even wisteria would grow though. Since moving to Seattle I have had much better luck w/o doing anything different then I did then.

To further push my point a friend of mine moved from north Seattle, where basic simple plants would grow great back to Troy and all his plants died within a few months.
I don't dose any Mg other than what comes in Flourish if there is any. I have considered on buying the dry ferts and mixing a bottle of Mg ferts for my tanks.
My co2 is now at the point that I can't turn the co2 up without damaging the livestock. I have already lost 6 CRS when I had the co2 too high and it ran out too quickly and gassed the tank. I think I may try collecting rain water and seeing how things improve.
The main thing that bothers me the most is the bba. Other algi are fairly easy to get rid of, but the bba is something that can take over easily and is difficult to get rid of especially if you have mosses and can't use excel to kill it. I have a lot of light on my 10g and I am now trying to do the noon burst because the bba is starting to grow more as well as other weird algi. The odd thing is that all the algi including bba are growing white or light green.

Avalon or Bert, have you tried mixing well water with RO water? I would imagine this would decrease Ca in the water and at the same time you would not have to add any minerals to the pure RO water and make the water softer. What do you think would be a good mixture?
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I don't have hard water, but I would like to encourage you all to embrace it. There are many species of plants which thrive in hard water that grow glacially slow in softer waters.
Point of information: <g>

When we talk about water hardness as it affects plants, aren't we talking about dissolved calcium and magnesium, or the GH? That is what's used for plant nutrition, with a very few exceptions.

KH refers to the carbonates in the water. It's main purpose is to buffer the PH,
although a few plants are capable of using it.

I think plants in an aquarium with a GH of 1 and a KH of 10 would be starving for mineral nutrients.

The water we get here in Florida comes out of the limestone and has both high amounts of Ca and carbonates raising the GH and KH really high.

I would not want the GH or KH to be low or high. The hard water has its benefits in that it has quite a few minerals for the plants and it certain plants flourish in it like some crypts. But problems arise like what Bert originally posted. I think it would be far better to have a tank that has a mid level GH and KH since most plants and fish enjoy the mid level.

I think though that the hard water is definitely beneficial when dealing with plants and animals that require hard water. I would imagine it is fairly difficult to keep hard water crypts when all you have is soft water. Then again its probably cheaper to make soft water hard than to make hard water soft.
Point of information: <g>

When we talk about water hardness as it affects plants, aren't we talking about dissolved calcium and magnesium, or the GH? That is what's used for plant nutrition, with a very few exceptions.

KH refers to the carbonates in the water. It's main purpose is to buffer the PH,
although a few plants are capable of using it.

I think plants in an aquarium with a GH of 1 and a KH of 10 would be starving for mineral nutrients.

This is a great point of discussion, probably the point of discussion. :) It's my opinion, and I understand that others may feel differently, but GH is far overrated. To set some sort of basis for my opinion, I tend to run moderately lit tanks because I can grow anything under moderate light. It may take a little longer, but I'm in no hurry and it's beside the point. Possibly under high light conditions GH may play a factor, but I've yet to encounter a situation where Ca or Mg has played a factor in plant health, and that's a lot of situations. I've got 2 lbs. of GH booster collecting dust underneath my 100% RO water tank.

I know that KH on paper tends to serve as a buffer for pH. But why does it influence plant health so greatly? KH doesn't seem to actually do anything (on paper). Why can you not grow Tonina's, Erio's, or have Rotala macrandra flourish in high KH water? Why do plants undergo extreme die-offs when the KH level is substantially altered? I lost an entire field of Pogostemon helferi when I switched to RO from the hard tap water I was using. That, I don't know, but it's something I'd like to understand. All I know is that from my experiments and observations, it works. KH substantially affects aquatic plants. Since moving from high KH water to low KH water, everything I put in my tanks flourish when I meet their nutrient conditions (NPK, traces, iron, CO2, light). BBA is not to be found. In every single high KH tank I've had, BBA was always present. It may have been in tiny amounts and controlled, but it was always there. With my RO tanks, I've yet to see it.

Having said that, I've run my latest tanks with 0dKH and the only source of Ca and Mg being from my trace fert and whatever ionic content is left-over from the RO water since I don't use de-ionization (TDS = 12 on average). They love nitrate to the tune of 6ppm per day. I don't have anything in the tank that leaches Ca or Mg. I was ready for the GH deficiency, but it never showed up to crash the party. I know the lack of KH and or GH on paper makes sense, but practicing it is truly making me re-think things.
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I agree, that it's the kh which is causing most of the issues, not the gh. Though in my case, as I said, I need to dose Mg (Epsom salts) or I get lots of stunting.

I don't have problems attaining and maintaining CO2 levels, but I do have to run it 24/7. I tried the solenoid way and quickly found it wasn't working.

Yes, BBA is always there just lurking beneath the surface. Folks bad mouth SAE's because they will eat certain plants, but they are the ones that, at least in my tanks, keep 2 of them bba free. I have them in the 2 50's and there is no bba. In my 10, I don't have one, and while the moss does fairly well, so does the bba, and I have tons of CO2 there.

I have never tried mixing rain water with my tap. I would find it too much work to collect, and them have to mix it in. Then what happens when you get a dry spell? :) But if you do it, I'd like to know the results.
Bert, I agree with your observations about nutrient levels in hard-water tanks. People who are big proponents of EI are, on average, those who live in hard water areas. My own experience is that EI works much better when the KH is high. In my RO tanks, EI hasn't ever worked real well. I get ok growth, and not too much algae, but the plants don't look as healthy as they do with lean dosing. They also grow more slowly and I see more stunting issues.

At the same time, trying to run a hard water tank lean is asking for trouble. I suspect this is a fairly complex issue. It probably relates to the cellular mechanisms that are responsible for how plants transport various nutrients. As one example, high nitrogen levels in a low KH tank will sometimes produce an apparent Ca defficiency, even when Ca is abundant.

Die-hard EI proponents will agrue against this observation extensively. My observations aren't scientifically founded or proven. They're just what I've seen over the past three or four years that I've been playing around with this.


I think the signifigance of KH lies in the concentration of carbonate in the water. It's well established that certain plants, like Vallisneria, can assimilate carbon directly from carbonate. In fact, those same plants don't do well in soft water systems. Carbonate is arguably a hugely important "nutrient" in its own right and its presence probably influences the uptake of other nutrients as well.

One thing that has driven my own attempts to run my aquariums on the lean side is analysis of waterways where these plants are found in nature. Most river and stream systems have incredibly low levels of nitrates, phosphates, and micronutrients. The sediments in the streambed are often no better. Despite this, the plants thrive. They do this despite fairly low CO2 levels and under full tropical sunlight. How can this work? My own thoughts are that the plants are keenly adept at assimilating nutrients from very dilute concentrations. The one difference that we have in our artificial systems is a limited water column. It is very easy for our nutrient levels to swing wildly back and forth from plentiful to almost absent. In nature the continual waterchange keeps things fairly contstant. The sudden depletion of a given nutrient would be pretty uncommon.

It's probably a true statement that a larger number of aquatic plants will do well in soft water compared to those that will do well in hard water. For me, it's just less frustrating to use RO. I love Rotalas and several other delicate stem plants. Many of these just won't live in a high KH. The list of plants that can't grow in soft water is pretty short.
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Try doing this hobby in water that is 16 KH and 24 GH. Higher than usual Mg, almost 1:2 Mg:Ca. A real PITA.

I had to settle for the simple plants, and even they don't do great. Letting the tank run low on N is the worst thing I can do. It's a 90 gallon with a 250W 6500K and a 175W 14,000K MH for noontime. Ridiculous amount of light, and sluggish growth. The green dust algae is my bane, but easy to clean off.

For those of you fighting BBA, try removing the driftwood. Yes, I know it's part of the 'scape but you will do yourself a big favor without it. It's several -pounds- of dead stuff, for which BBA is evolved to decay it. Worked for me.
I too have very high KH and GH (20+ for both) and I need to get another kit to test it again. I have noticed that most of the plants do allright and haven't had that much problem growing a lot of plants but there are certain ones that I can't grow or haven't done too well.

As far as CO2, I can't say if its difficult to keep it high in my tank or not. I have a pressurized system and they drop checker is yellow by the end of the day but the fish are swimming around with no problems. I also notice a lot of pearling as well so I can only assume that I am dissolving the Co2 ok.

The biggest problem would have to be fertilizing...I still haven't figured out exactly how much is too much and I constantly feel I'm under-dosing, even though I'm going with what the fertilator and chuck's calculator tells me. Hopefully when I go back to school in a couple of weeks (where the tank is) I can better mess with it and see what happens.

While I realize this is more geared towards plants, I wanted to ask about people's experience with keeping fish in hard water. I'm in the process of deciding on what species to keep and would like to know which tetras/cichlids/etc have done well in hard water. The reason I ask is because I can't seem to keep a school of any tetras for longer than a few months. I've been thinking on what could be the problem with a sudden death of a single fish on a random day and while I know there are many factors, I can't help but think the hardness of the water plays a larger role than most people think. What's your take on this?
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I'm in the process of deciding on what species to keep and would like to know which tetras/cichlids/etc have done well in hard water. The reason I ask is because I can't seem to keep a school of any tetras for longer than a few months.
Though I currently do not have any, I have kept cardinals alive for 3-4 years in my water.
Fish that come from soft water usually store minerals with greater tenacity than fish from hard water. When soft water fish are placed in hard water they continue to store minerals as they are genetically set to do.
I would choose fish that come from hard water to live in hard water, or properly prepare water for the soft water fish. (RO, RO/DI, peat...)
Fish that have been bred in captivity for several generations seem to handle the harder water better than fish that have not been selected (accidentally or on purpose) for such a setting.

Hard water fish:
Many Livebearers
Rift Lake Cichlids and other fish
certain Rainbow fish
Some low end brackish water fish will be fine in 'liquid rock' without adding salt. Look for fish that are normally found not only in the estuary, but also travel up the river into fresher water. Avoid brackish water fish that gradually move out into the ocean as they mature.
Indian Glass Fish and Bumblebee Gobies come to mind.
Bert, I have water with kh of 12-15 and also live over a limestone aquifer in san antonio. I agree with your points and have found them all to be true to some degree. esp the stunting. in fact i have some l. senegalensis that 'adapted' to this water and the color is great but the leaves are about half their normal size. its going to the for sale section soon cause i cant deal with a plant not reaching its potential in my tanks. running the tank lean i have found is not a good idea. i tried this in my 2.5 to attempt to bring out the orange in my l. brevipes and algae started taking hold-green dust. since i started dosing more growth is better but no more orange ludwigia. anyways good observations here always learning something here.
My tank has a Steady PH of 8.4 and High GH(about 23dH or between 320 and 530ppm) and KH (about 12-15dKH), I have tried a Ton of plants all have died except 2 sword plants(i would like to have more than just Swords)I have tried a few different plants. Java moss,Java Fern, Anubis, Dwarf Hair Grass,Waterlily,Barclaya,Aponogeton and a few others i cant remember the names of, All have Died some quicker than others. I am running 108 watts 10,000 T5 HO lighting and DIY Yeast CO2 Injection. And i have some type of Sword that is the ONLY plants that haven't died. it is a 55g tank Freshwater. with a pretty heavy fish i know i am getting tons of fertilizer. But As i Said the water is Very close to African Rift Lake conditions(even though this isn't what i wanted i just had to use what i had on hand), and i am really having a hard time finding plants that will grow in it. So i really feel your pain on the Hard Water Issue. Im gonna try some Vals and See how they do, The plants i have been told to try such as Java Fern,Java Moss and Anubis have all died. I just find it hard to believe that NO plants grow in African Rift Lake's! Or is it that we just cant get the plants that DO grow their HERE in the states?
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Is RO/DI not as popular in planted tanks as it is in reefkeeping? Almost everyone serious about reefkeeping has one. I am just getting started in planted tanks and bought a 150GPD unit that takes my 480ppm tap water down to 11ppm after the RO and down to 0ppm after the DI.
Hope for all you rift lake tank keepers and Liquid rock havers!!!!!! Below is an email i recivied from a Biologist who specializes in Invasive Aquatic plants. YA for talking to the experts!

"My experience is mostly with invasive's like hydrilla which you don’t want to use. I know that Vallisneria does well in alkaline, hard waters. I think Myriophyllum and Bacopa do Ok in hard waters too. Some aquatic plants can absorb the carbonate salts and strip away the carbon from them, and use that as their carbon supply. The list of plants capable of doing this includes many that do very well in aquaria, including Ceratophyllum demersum, Cryptocoryne becketti, Echinodorus bleheri, Egeria densa, Elodea canadensis, and Vallisneria spp — all popular and easy to obtain species. If you have hard water and don’t want to be bogged down with carbon dioxide fertilization, then these are definitely the plants for you! Admittedly, some of these plants are fussy in other ways. Echinodorus bleheri, for example, needs a rich substrate and good, strong lighting, but Ceratophyllum demersum and most of the Vallisneria are adaptable and easy to keep. If you want to keep live bearers, then Ceratophyllum demersum is difficult to beat as a floating plant that provides a refuge for newly born fry. Egeria densa, on the other hand, is a sturdy, fast-growing species ideally suited to subtropical tanks. Vallisneria spp. are perhaps the most versatile aquarium plants."
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