Need help with tannin removal.

[CHOMPERS]

My city water is loaded with chloramines, and is pretty much unusable. I have been using lake water for my aquariums but it has far more tannin than I care for. Since last years hurricanes it has gotten worse. The tank constantly looks dirty and amateurish. (I realize that having goldfish doesn't help.)

I am looking for ideas or ways to treat the water prior to adding it to my tanks. I would like to set up a water treatment system that is as automated as possible.

So far, the only thing that has worked for removing tannins is chlorine bleach. But I would prefer to avoid it if possible. I have noticed that concrete blocks in the lake have absorbed a concentration of tannins, so this has been my focus so far.

My first experiment was adding water to a bucket that had been used for mixing concrete (with a layer of cement remaining). After sitting overnight, the pH had risen to 8.4 but there was no improvement in the clarity. Three days later, still no improvement.

The second experiment was two bottles of lake water. One was a control and the other had the addition of baking soda in 1/4 teaspoon increments until a change occurred. The change never occurred. I added six doses and figured it just needed some time. After letting them sit overnight, there was zero change and no sign of any precipitation.

The third experiment is in progress, but I am having reservations to the outcome. I added two reactors to the sump. One has crushed coral and the other is just filter floss to monitor for any precipitation. This experiment is on hold for now. I need to monitor for ammonium/ammonia, but I have to wait for a new test kit. The lake water's pH is 7.0 but the aquarium had dropped to 6.0. The effluent of the reactors is 7.6, so it is showing some potential. At the very least, it can prove useful in maintaining the pH if there isn't a problem with ammonium or ammonia.

As stated before, I had success with bleach and it sent me down the road of trying ozone. My goal at the time was just to sanitize the water and clarity should have been a fringe benefit. The smell of the ozone was unmistakable while in use, but it did nothing for the clarity unfortunately. I don't know why.

Any ideas or information will be greatly appreciated

 

[jjohnwm]

I will be following along with great interest, although I have no suggestions regarding how to help. I know that tannins have beneficial qualities, but...I hate the look. My single in-ground backyard pond usually has several pieces of wood that I am soaking, and together with the leaves that accumulate each year, this stains the water to look like weak...and sometimes not-so-weak...tea. I find it detestable.

My aquariums all get lots of water changes, so usually the tannins don't build up to the point where it is noticeable although almost all of them contain at least some driftwood. In particular, I have a 40breeder that houses a single rapidly-growing axolotl, and it contains a single decent-sized piece of driftwood; the wood was gifted to me and it is the only piece of wood I have that was not self-collected from nature. It's one of those weird tropical woods that is so dense that it sinks naturally, no water-logging required. It has been continuously submerged for probably 5 or 6 years now...but if I let the tank go without a water change for more than a week, the colour starts to become visible. It keeps me honest...

How does chlorine bleach work for you? I assume that by using it, your are essentially chlorinating your natural lake water, to be used in place of your "chloraminated" tap water? Since tannins are in solution, and not a simple suspension, how does the bleach work to remove them? You also mention "precipitation"...does the bleach somehow precipitate the tannic compounds into a solid that is then mechanically filtered out? You also refer to the clarity of your water; water can be heavily tannin-stained, i.e. coloured, while still being "clear", i.e. not cloudy with suspended matter. It sounds as though you are dealing with both issues at once?

I must commend you on your dedication to the hobby; you and others who must go to great lengths just to provide enough water for your tanks impress and humble me. I don't mind doing a little or a lot of work to create a system that makes things easy going forward...but if I needed to treat all water on an ongoing basis by RO or some chemical means to keep my hobby going, I suspect I'd be looking for a different hobby.

Good luck, I hope you keep us posted on developments.

 

[esoxlucius]

Tannins are beneficial to your fish, though as John alluded to, they aren't everyone's cup of tea, pardon the pun!

Activated carbon will remove most of the tannins, and any odours too. Have you thought about going down that route?

 

[duanes]

Tannins are beneficial to your fish, though as John alluded to, they aren't everyone's cup of tea, pardon the pun!

Activated carbon will remove most of the tannins, and any odours too. Have you thought about going down that route?

Agree
They are antibacterial, and at the beginning of the rainy season my tank gets inundated with them, which I welcome.
Being organic, they do degrade and disappear after a while.
I had chloramines when I lived in WI, and just used a simple dechlorinator to remove them.

Left pic, Chloramine concentration before adding sodium thiosulfate, right after using sodium thiosulfate. Most commercial dechlorinators work in the same manner and use the same ingredient.

But these days, I welcome the temporary addition of Tannins.

Tannins are especially beneficial if one is keeping Amazonian species, like Oscars, Rams, Uaru, or other soft water, black water species, helping to prevent HITH.

 

[jjohnwm]

Tannins are beneficial to your fish, though as John alluded to, they aren't everyone's cup of tea, pardon the pun!

Activated carbon will remove most of the tannins, and any odours too. Have you thought about going down that route?

Lol, I was thinking about suggesting activated carbon or something similar...but that becomes pretty impractical as the volume of water being treated increases. If I had to treat all my water continuously with carbon I would be buying it by the truckload. OP hasn't mentioned size/number of tanks but I get the feeling we aren't talking about a single 10-gallon in the corner of the den.

Yeah, yeah, I know...recharge the stuff in your oven. Try doing that with large quantities of carbon a few times and see how you feel about the idea...

I agree with duanes about certain fish almost demanding soft, tannic water. My solution is simple: I don't keep those fish!

 

[TwoHedWlf]

My city water is loaded with chloramines, and is pretty much unusable.

What makes the water unusable? Just because it has chloramines? With Safe even if you're double dosing it because of high chloramines it still would only cost about .02 cents per liter.

 

[CHOMPERS]

I forgot about failed carbon attempts A and B.
A was the larger carbon block filter. It was previously very lightly used but the color was the same coming out as going in. (It was originally used to try to remove the chloramines from the tap water.)
B was the redo with the dual setup. The pre-filter was a brand new one micron cartridge, followed by a brand new carbon block cartridge. The result was the same. I repeated the test but I reduced the flow rate to a trickle to maximize the contact time. It didn't make a difference.
I don't know what I am dealing with in the water, but it shouldn't be this difficult. The lake is a mile long and half a mile wide, however it does get receive run off. Officially it is not polluted and is healthy, but I don't know if that has really been verified. I am having my doubts.

 

[CHOMPERS]

This is the result of the Sodium Bicarbonate test. The bottle on the right received the Na2CO3.

 

[CHOMPERS]

How does chlorine bleach work for you? I assume that by using it, your are essentially chlorinating your natural lake water, to be used in place of your "chloraminated" tap water? Since tannins are in solution, and not a simple suspension, how does the bleach work to remove them? You also mention "precipitation"...does the bleach somehow precipitate the tannic compounds into a solid that is then mechanically filtered out? You also refer to the clarity of your water; water can be heavily tannin-stained, i.e. coloured, while still being "clear", i.e. not cloudy with suspended matter. It sounds as though you are dealing with both issues at once?

The bleach test worked great, but I needed to use more than I expected. There was no precipitation. That thought came from someone's result of using Sodium Bicarbonate. In my experience with bleach, there was never a precipitant. My use of it comes from 30 years in the swimming pool industry. When a pool is filled with Florida water from any source, it is always very yellow. After adding several jugs of bleach, the pool will usually be clear within 60 seconds. I'd prefer a straightforward method such as carbon filters or precipitation, rather than chemical treatment. However, it won't be the end of the world if it is my best solution.

I'll try to post a picture of the crushed coral setup. It follows on the idea of precipitating the organics and capturing them in filter floss.

Currently I only have two tanks running. If you can go through my old threads, you can get an idea of my former fish madness. At one point I had 24 tanks running and the swimming pool was converted into a koi pond. During our move nine years ago, I gave away a 400g and 110g tank. I kept a 250g, 180g, and a 120g (and a slew of smaller ones). However they are all empty. I have been wanting to set up the 180g as a native tank, and possibly the 250g. The water has always been the hang up, and I am only now getting serious about it.

 

[CHOMPERS]

What makes the water unusable? Just because it has chloramines? With Safe even if you're double dosing it because of high chloramines it still would only cost about .02 cents per liter.

I have a drip system addiction (& manual water changes are my Kryptonite). When I moved into my current home, I tested the water after the carbon filter. It was still present. I don't know why or how, but it was there in sufficient quantities. I then made a system that contained six gallons of activated carbon. That should have solved the problem, but apparently I am cursed. I gave up on the city water at that point.