melev

Yep. I'm on still on a well and loving it.

We got spring water here

Are you running a booster on your RO? I get traces without a booster running here... Our Tap is about .5 usually.
Another trick is to throw some PolyFilterTM in the top off and have the pump pull the new water through it when topping off. I used that before I figured out the booster trick.

In my thinking the booster pump on the system, which helps pass more water through the ro membrane, would be more likely to allow ammonia through.

I am using a booster pump on a 150gpd membrane.

I don't understand the concern... if there is an abundance of beneficial bacteria in our tank, it will immediately convert the ammonia right to nitrite and then to nitrate, the same way it converts the ammonia from fish waste. Isn't that the whole purpose of the bacteria?

I can understand that if the water change was in excess of let’s say 30%, dumping that much ammonia could be a cause for concern. But having it added slowly at the rate of our tanks evaporation, is pretty consistent with fish waste and feeds the bacteria at a steady rate, keeping the bacteria robust.

The only problem I would see is, by adding more ammonia it’s like having a larger bio load which leads to more of the end product in the form of nitrates and phosphates which becomes a battle for a lot of us, but again these days there are products and other practices that can lower them such as biopellets, carbon dosing, algae scrubber, deep sand bed, macro algae etc.

I would be interested to see an ammonia test done with newly mixed salt water prior to adding it to the tank and an ammonia test 2-3 minutes after the water change (allow the new salt water to spread throughout the tank) and if the readings detects ammonia, continue to test the water every 5 minutes until ammonia reached 0 again.

Jimmy

From from the discussions Ive had with the water treatment people I buy stuff from, the higher the pressure, the more the membrane tightens up, and the higher the rejection rate. Our tap is about 65psi, where the membrane works most efficiently at 90psi. Without the booster, I get tds7 out of the membrane, with it running, I get tds5, to me, that means its rejecting more. A few of the Discus breeders I know have also seen the same thing, they are VERY nervous about residual ammonia, as they are doing huge daily water changes. Even though the ammonia is supposed to be small enough to flow right through an RO, it seems to happen to a lesser extent with higher pressure on the membrane IME.

The concern is that residual ammonia level via top-off, means less food that Marc can feed his fishes. If he gets rid of it, he can add another meal a day!

Jimmy, I would never want to knowingly add ammonia to my system in addition to what the livestock and breakdown of food and waste provides already. If you are willing to do so and perform that described testing, let us know your results.

Jonathan, I have a booster pump running between 80 and 100 PSI depending on water pressure coming into my home. I definitely have enjoyed better efficiency due to the booster pump, keeping TDS more around 1 instead of 6, and the DI resin lasts twice as long or more. Be that as it may, it is only taking out 50% of the ammonia the city is offering us in our tap water. Prime locked it down, but some people don't usually check this nor do they think they might need to add some type of product to assure the water is safe enough.

I'll test my RO (two hours east of Dallas) tomorrow and see what I come up with.

Interesting post Marc, thanks! :-)

I always have ammonia in mine from the chloramine they use in our water. I tailor my ro/di filter selection to them and it helps keep it out of my tank