The last time that I updated how my tank is doing with PPS pro, I mentioned that I wouldn't do anything major that might affect the test results. Well, I did anyway. On December 22nd I added ten new species of plants that were given to me by jeremy1, and also removed some of my plants to make room for the new ones. I'm not sure how much if any this will affect the nutrient uptake, but what's done is done so we'll just have to wait and see. Also, I went out of town for a few days over Christmas, so the fish didn't get fed any during that time. I'm also not sure how much that will affect the test results. Never-the-less, I performed a LOT of water testing on January 3rd, but am just now getting around to posting the results (been really busy at work - putting in lots of twelve hour days).
First-of-all, a few days before doing the testing I opened up the hood to feed the fish and was greeted with an all too familiar but very unwelcome smell. Believe it or not, I used to have such a terrible time with cyanobacteria (BGA) back in the nineties that I can actually smell it in the water! I immediately started looking for it and found a tiny little bit (about as much as a pencil eraser) on some of the Cabomba right on the growing tip near the surface. I removed it and couldn't find anymore. This worried me that I might have gotten the nitrate levels down too low. Upon checking it I found it to be 8.5 ppm. This makes me think that I might ought to aim for the 10-20 ppm range, since I definitely don't want this stuff to return (it almost made me leave the hobby). I've since increased the nitrates again and the smell and BGA is gone.
The phosphate test gave me a result of 1.5 ppm, but I'm not sure if I can trust that reading. The reason is because when I added the first drop of reagent from the Seachem kit, I noticed that it was actually the
last drop in the bottle. I am not totally convinced that the exact amount made it into the water sample, so the reading might be wrong. Another reason why I think that is because I've been studying the plant deficiencies charts, and the Hygro. polysperma still isn't doing as well as is should, and to me it really looks to match the pictures of a phosphate deficiency. As I mentioned before, I'm still not really sure what level to target, but until I get another way to test it, I don't want to fool with the levels too much. I'm going to order new reagents for my old LaMotte phosphate test kit (I meant to do it this week but got too busy at work) and will see what kind of levels it detects. I may increase the amount of KH2PO4 even more than I have been, but I'm not sure yet.
The iron tested at .2 ppm just like last time, and the Mayaca fluviatilis is growing like a weed. My guess is that the Fe levels are okay. Here are some pictures of the Mayaca taken on January 4th:
I've been trimming and replanting, but I think for the first time I'm going to have more trimmings than I know what to do with. I think I'm going to call the LFS and see if they can use any.
The potassium tested to be about 30-35 ppm. Last time I mentioned that I wasn't sure what I was going to be able to do if the potassium levels were actually too high. However, later I remembered that one of the main PPS pro ingredients is potassium sulfate. After doing some more research, it appears that this is added mainly for the potassium and not so much for the sulfur. Therefore, my guess is that I could reduce the K2SO4 if I need to get the potassium levels down. I'll have to think more about that later.
After doing lots of research here on APC, I decided that I would like to know what the Calcium and Magnesium levels are in my tank, my well water, and my tap water (after going through the acid neutralization tank that I mentioned earlier in a previous post). I bought a LaMotte Total Hardness/Calcium Hardness test kit so I could find these levels out. I have been wondering if I really need to be adding the Epsom Salt (Magnesium Sulfate Heptahydrate). I've been using an Aquarium Pharmaceuticals GH/KH test kit, so I decided to test with both kits so I could compare the readings. I tested the water in the tank, the water coming straight out of my well, and the water coming out of the tap. Here are the results:
Tank water - LaMotte kit Total hardness, 160 ppm (9 degrees); Calcium hardness, 88 ppm; Magnesium hardness, 72 ppm - API kit GH 11 degrees
Well water - LaMotte kit Total hardness, 100 ppm (5.6 degrees); Calcium hardness, 64 ppm; Magnesium hardness, 36 ppm - API kit GH 6 degrees
Tap water - LaMotte kit Total hardness, 164 ppm (9.2 degrees); Calcium hardness, 112 ppm; Magnesium hardness, 52 ppm - API kit GH 8 degrees
It appears to me that with the well water and tap water, the LaMotte and API kits aren't too far off from each other when it comes to the Total/GH hardness, but with the tank water they aren't that close. I actually went back and did those tests again since I thought that I might have made a mistake, and still came up with the same results. I have been researching here on APC until I'm cross-eyed, and I can't find anything that provides an answer as to whether there might be some explanation for this.
As I said before, the reason that I did all of this testing was because I wanted to know the ratio of Ca to Mg, which I found to be at 1.2:1. After lots more research, it seems that it should actually be somewhere around 3:1 to 4:1. Unfortunately, the information is spread out over many posts and I sometimes wonder if what I'm reading is really all that useful. I remember reading a post about how if various different elements ratios (Ca, Mg, N, & K, maybe? ](*,)) are off then you will get deficiency symptoms in the plants, even if it appears that you have enough of everything, but I can't find it again to save my life. Regardless, I think that I need to reduce (if not stop) the amount of Epsom Salt that I dose since it appears to me that I have more than enough Magnesium. In fact, I'm curious if having an excess of Mg might be causing other nutrients to not be taken up by the plants.
While testing all of this water, I also tested the KH using the API kit, so here are the results:
Tank water - 7 degrees KH
Well water - 5 degrees KH
Tap water - 7 degrees KH
I'm not sure if I should get an alkalinity kit from LaMotte or just stick with my API kit.
After all of this testing, I decided to go back with the dosing that I had been doing before I tried to get the nitrates down further. I added the Macro solution to the infusion pump that has only 25% of the KNO3 that the recipe calls for, but with 200% of the KH2PO4, but when I run out of it I think I will tweak the ratios some more (primarily the Epsom Salt).
Andy