RO water and wild discus...can TDS be too low?

[jcardona1]

Hey folks,

I tried searching for discussions on TDS but searching for 'tds' doesn't work, no results come up

My question is, what is a good TDS level to aim for when using RO water with wild discus? And also, what are the TDS levels normally found in the wild?

I've been using RO water in my 190g for a few days now, and my TDS is slowly starting to come down. I started in the mid 300s and now I'm in the 220s. My 30g QT tank that has a group of wilds has also been getting RO water for water changes. The TDS in this tank is in the 70s. On the 30g, I add Kent's RO Right when adding new water. On the 190g, I've been adding pure RO water to bring the TDS down. When it gets to a good level, I'll start up with Kent's product.

Another member mentioned in my past thread that he uses pure RO water and his TDS is very low, like 15 or so. Would this be safe for other fish as well? Because I have more than just discus in the tank.

Thanks!

[DiscusLoverJeff]

Jose,

I read on a few threads a while back that TDS of 100 - 120 is not only good for domestic discus but as well for wilds. I will be setting up a tank for wilds myself and that is the parameter I will shoot for. I do know however it is a lower number for breeding around TDS 75.

Here are some articles I found.

http://www.aquariacentral.com/forums.../t-213227.html

[DiscusOnly]

I don't use RO but my water out of tap through a whole house filter is in the 120s and the wild are very happy. No issue with keeping domestics in these water either.

Van

[roundfishross]

I dont keep wilds but for breeding pairs I shoot for around 60 to 80ppm while they are spawning, during off cycles they get bumped up to around 120 to 150ppm. for fry growout I shoot for the 350 to 450ppm range. this is all tap water my tap is about 50ppm. fwiw I have tried ro right(when using ro water) and did not like it at all the ph was higher than I liked it to be. the sera remineralizing salts worked well though....Leo

[jcardona1]

Thanks folks. Seems like aiming for levels of 70-100ppm TDS should be good. My TDS is a little over 100 out of the tap, but it was much higher in my tank. Anybody keep wilds in TDS less than 50ppm?

[roundfishross]

hekel keepers do I think

[Discus Origins]

According to Heiko, what he has found in the wild is that conductivity avgs between 20-40 uS. Using a conversion factor of TDS x 0.67 = conductivity, that puts Amazon water at around 13.4-26.8ppm. This is for locations where Blues, Browns, Greens, and Heckels were found. So depending on your goals, if you want to keep your wilds in their natural conditions....I suggest you use pure RO water and add Kent Discus Essentials. My water settles at 15ppm, 4.8-5.0 pH and the additive doesn't change pH.

People keep discus in all kinds of water conditions and even breed them in water above 150ppm sometimes. But if the goal is to duplicate natural conditions, then your water should not be above 26.8ppm and below 6.5ph

[jcardona1]

According to Heiko, what he has found in the wild is that conductivity avgs between 20-40 uS. Using a conversion factor of TDS x 0.67 = conductivity, that puts Amazon water at around 13.4-26.8ppm. This is for locations where Blues, Browns, Greens, and Heckels were found. So depending on your goals, if you want to keep your wilds in their natural conditions....I suggest you use pure RO water and add Kent Discus Essentials. My water settles at 15ppm, 4.8-5.0 pH and the additive doesn't change pH.

People keep discus in all kinds of water conditions and even breed them in water above 150ppm sometimes. But if the goal is to duplicate natural conditions, then your water should not be above 26.8ppm and below 6.5ph

Thanks Mark, I remember you telling me about how low in TDS your water was. I checked Hudson's thread, and he also said he's seen levels of 10-60 uS in the wild, so that would mean TDS levels of 6.7~40ppm! That's pretty low. His personal tank is at 120 uS, or 80ppm. I've still got a ways to go to get my water down there since I'm doing 40g daily water changes. I find that TDS drops about 40-60ppm each time I do a water change with pure RO water.

[Jhhnn]

If the hardness in the tank is higher than the hardness from the tap, I'd suspect there's something in the tank leaching minerals into the water. Hard to say just what, but until that issue is solved, you're fighting an uphill battle... Or it's a very old aquarium system, where water hasn't been changed, just added to maintain the level. I've actually seen that in my used tank buying adventures.

Soft water is fragile, meaning that it has very little buffering capacity. Natural aquarium processes tend to acidify the water, so PH can change quite quickly in very soft water... drop like a stone, to the detriment of your fish. Discus can take it better than most.

[Melissa]

So... When using pure RO water and remineralizing it with Kents Discus Essentials, is the water stable? What is in the Kents stuff? And Does the Kents product add back buffers?
When dealing with soft acidic water, Is there a technique or maybe a rule of thumb for water changes and maintenance to keep 'Natural aquarium processes' from dropping the ph too quickly and adversely affecting fish? I guess my question is... How would one go about being as safe as possible when using pure RO water and remineralizing it?

[Darrell Ward]

I don't use RO, but my well water has practically no buffering capacity at all. My water would freak some fish keepers out! It is extremely fragile, and my normal PH of 6 can drop drastically if ignored. To combat against this, my water changes tend to be 50 to 75% about every 2 days, in larger, understocked tanks. I rarely ever use a tank under 75 gals., and the largest tank I've used has been 300 gals. I've been doing this routine for years, and I'm so used to it, I can predict with a good deal of accuracy when I'm going to need to do a water change based my stock levels, and feeding amounts in a given tank. I suppose I could buffer my water, but my system works for me, and have raised countless fish using this method, so I see no need to change it.

[Discus Origins]

Kent essentials does not help buffer water but will raise TDS slightly. If you are only adding pure RO water during water changes there is no need to worry about ph drops, the RO water just conforms to tank conditions. I've never had any 'natural process' ph drops or spikes...unlikely to happen adding RO.

Like Darrell said, more WCs will keep your ph a little higher. I only do water changes every 4-5 days in my adult heckel tank and the ph stays at 4.0-4.2 while my RSGs stay at 5.5 with WCs every other day.

[Melissa]

Hmmm... So if I keep 8 wilds in a 125 gallon tank, would 50% water changes every other day be sufficient if using pure RO water? It really scares me hearing about ph crashes and huge ph swings in unstable water, but I think from what vie read, to simulate their natural water conditions, pure RO is the way to go. I think someone told me once just adding a very small amount of baking soda will bring the KH up. Had anyone else done this?

[Discus Origins]

Melissa, I keep 10 adult wilds in a 90g and do WCs every 4-5 days with no problems. Don't add anything except RO water and discus essentials. Only overfeeding can mess up water parameters, I feed my adults at the most twice a day as that's all they need.

[Melissa]

What do you feed them mark? Just out of curiosity