Nope. Have always just added directly to the tank. From back in the day of HOB filters with Prime or other chlorine removers to now a days with a line ran directly from the drip filters.
I have hard water. So hard that I have no choice but to use external pumps. Couldn't get a pondmaster to last 2 years if my life depended on it. Hard enough that pot scrubbies could be weapons of destruction after a year in my water. They become hard enough to easily throw through a window if they're used submerged. My local pool supply store tested my water with thier fancy computer and PH was 8.6+, topped thier machine out. It doesn't matter if I drip 100 gallons a day or 500 my rays look like hell, don't breed, and based on the amount others feed they eat half as much and grow half as fast. But year after year I'm told the same thing - "Rays adapt to anything. You can keep them in any water and they'll be happy" Who am I to argue with the people here that are breeding rays like rabbits? I see pics of pups posted here year after year and can't help but think something's seriously wrong, but every time I try to get help I'm led in that familiar vicious circle - Rays adapt to anything. So I redo my filtration, cause something's not right and everyone seems to think it's not the water. Well, I'm sick of stressing over it. I'll change the water and if that doesn't help then it might be time to leave the hobby, or at least the Marble part of it.
Just tired of feeling like a failure, cause let's be realistic, that's all this whole Marble endevor has been. Aquire the nicest ones I can find regardless of cost, fail to breed them, watch the pattern deteriorate so bad that a $1000 Marble turns into a $300 Marble in a year or less and have to sit back and watch everyone else's rays get nicer by the day, breed, and grow. It's gotten to the point that even thinking about it makes me sick. Year after year watching it gets harder and harder. There's only so much you can take before giving the whole endevour a big "F" you. The water experiment will either fix my problem and solve alot of unanswered questions or it will land my Marbles in the care of others. No point in participating in borderline crulety to rays just by having them at my place.
