Andy Ritter

I'm sorry that you've had issues, Neil. I have never had issues with precipitates clogging up the tubes on mine. Every once in awhile (probably every couple of months) I'll knock off some crust from the ends of the tubes, but not because it was causing a problem, but just because it doesn't look good.

You may have been following along on this thread where I have been experimenting with my PPS pro recipe. I usually only mix up 500 ml or less at a time in order to allow me to tweak the recipe for the next time if necessary, but I can tell you what my concentrations are currently compared to yours.

If mixed in 1.5 liters of water, my macros would have about:

11.2 grams KNO3
10.2 grams K2SO4
11.3 grams KH2PO4
7.1 grams MgSO4
1.5 ml Methylene Blue for fungus prevention

This solution is then dosed at .6 ml per hour into a 75 gallon tank.

As you can see, my recipe is mixed considerably weaker than yours, so less precipitate would be expected.

However, I started out using the PPS Pro regular recipe, but mixed at 1/2 strength, which if mixed in 1.5 liters of water would have:

48.8 grams KNO3
44.3 grams K2SO4
4.5 grams KH2PO4
30.8 grams MgSO4

I never had any issues with precipitates with this recipe either. You said that you tried mixing in 3 liters of water, in which case your recipe would be weaker than this, yet you still had precipitates.

As far as my micros, if mixed in 1.5 liters of water, they would have about:

30 grams CSM+B
1.5 ml Methylene Blue for fungus prevention

This solution is then dosed at .2 ml per hour into a 75 gallon tank.

As you can see, my recipe is about twice as strong as yours (but still only 1/4 strength compared to the PPS Pro recipe).

I'm not sure what to tell you. I have my tubes pointing straight down right above the full water mark of the tank (there are actually some pictures here). I would guess that you have yours dosing into your sump. I don't know if that makes a difference or not.

As far as the alarms go, I finally got an "Air In Line" warning this week, but only because I've been so busy that I goofed up and let the graduated cylinder run out. There wasn't anything wrong; it was just doing it's job.

I sure hope that you're able to get it straightened out.

Andy

nfrank

As Andy mentioned, i have a sump. The end of my tubing is inserted directly into the water. When you say nipple what do you mean. I just have the end of the tubing cut off.

Three things i can think of that might be different among our setups, but not sure if it would make the difference.[ I have a feeling it is something very basic that i am doing wrong.]
1) I am not pumping vertically very far. However, seems like this would be easier on the pump.
2) My tubing set has injection ports. Could they be allowing air to leak in? This is the TUBING
3) The HCL may be reacting causing precipitate to clog.

BTW, I first used tap water, then switched to distilled water (from grocery store). Even with distilled, i had the air lin line problem. Regarding precipitate, i also have it at the bottom of the solution container which says 'something' is reacting with the solution.

BIGSTICK: Did you figure out how to conveniently inject once per day. Faster flow might prevent air in line.

Andy Ritter

Hello again Neil,

As you probably saw from the pictures of my set up, I don't cut off the ends of my tubing. I don't know if that would make a difference or not. Also, I'm using the exact same tubing that you are, and I'm not having any issues with air in the lines, so I don't think that you need to worry about that.

When I first set mine up, I thought about whether I should let the tubing come in contact with the tank water, and ultimately decided that I didn't think that it should. My thinking was that I didn't want anything that was in the tank water to leach it's way back up through the solution in the tubing and contaminate it. When I first mixed up PPS Pro, I didn't use the Methylene Blue because no one had mentioned in the instructions that you needed to add any fungicide. The result was a lot of fungus of some sort that I ended up having to filter out of my mixture, and then go back and add the Methylene Blue to stop it. I'm not a chemist/scientist, so I don't know what exactly allowed this stuff to grow. However, I figured that if it was able to grow so well in deionized water with these fertilizers mixed in, I was very concerned about what would happen if tank water was allowed to come in contact with it, considering who knows how many different types of other things (bacteria, other chemicals, etc) that might cause other problems. Because of this, my thought is it would be better not to let tank water come in contact with your solutions.

I'm wondering if you might also be having an interaction issue between the macros and micros since you're saying that the tubes are both placed in the water in the sump. I've read two different thoughts on this topic, and I don't know which is true. One says that the KH2PO4 will interact with the Fe and cause Iron Phosphate to precipitate out of solution, and the other says it won't happen. I don't know if it will or not, because I haven't tried, but either way, maybe it would be better to not even have any chance of that happening. I would suggest raising the tubes up out of the water in the sump and just let the solutions drip into the water instead and see if the problem goes away.

As far as the question of fast flow versus slow flow, I agree that faster would seem to cut down on precipitates, but mine are flowing way slower than yours, and I'm not having any issues.

Andy

bigstick120

Neil, I dont cut the ends off my tubing, I used pliers and removed the screw down looking part. I get the crust on mine. Removing it weekly or when I notice a build up seed to solve it. Im using pretty close to the PPS pro solution, I add more PO4 and WAY less MG. Mix at half strength.

nfrank

One end of my tubing set has the gizzmo that is designed to puncture a hanging bag and has a drip checker. The other end has the thing that is meant to screw into something. There is a check valve, so the fluid can only move one way.

Which are the parts that you guys leave, and why?

I like Andy's suggestion that it is better to not have contact between the tank water and the fluid; that 'might' cause tank water to move up the tubing thru capillary action and potentially create an Fe + PO4 reaction (-->precipitate).

When my wife is not around for a few days, i may try it again. It is not fun to hear the alarm go off at night.
This time without muriatic acid. "The perfect may be the enemy of the good."
To eliminate variables, it would also be good to get a new tubing set. I am using the sets that I bought on ebay.

bigstick120

I cut off the bubble counter/drip counter thing, if I could find a container that I could use it I would. I left the other end on, but I did pull off the bolt looking part of it. Ill take some pics if that helps.

pat w

I leave the tube set intact. The bag lance fits nicely into larger ID airline and flows just fine as does the delivery end . I run the airline from the bag lance to 1/8" ID rigid tube that fits down into the 2L soft drink bottle I use as a stock bottle. I run the tube through a hole drilled into it just below the cap. This will allow me to refill without touching the feed path. I then take the airline from the delivery end to a piece of rigid 1/8" ID tube I bent into a J shape that fits over the edge of the tank. I hang the drop check tube next to the pump which is mounted onto a piece of 1" dowel stock slightly flattened on one side and attached to the inside of one of the doors of the stand cabinet. It makes it very accessable when the door is open and leaves plenty of room for the tube set to clear the bottom of the unit.

As for the noise WHEN the alarm goes off. I just put an earplug (the foam kind you roll between your fingers before inserting in the ear) in the hole in the back where the alarm speaker is. You can still hear it. It just isn't as distracting.

Pat

chasintrades

Well if there was a ton of interest...

This lot comes out to about $18 each... (23 good and 3 bad)

http://cgi.ebay.com/Imed-Gemini-PC2-...item3361a988c2

bamboosharkbark

I was surprised by the direction that this thread took, in a positive way! Great work Andy, thank you very much indeed, you're quite a stand-up guy!

bamboosharkbark

hey everyone, Ive been able to locate many offers on ebay for the gemini PC-2TX pump but have not found any tubing compatible with this pump. If anyone has any they may be willing to sell me or knows where to find them please post.
Also to Ritter: Do you still order the tubing from the supplier whose number you posted? Also how's the pump working for ya now?

kind regards,
Sven