Automated Dosing with Pumps ?

I've been using dosing pumps for a while. I use the AquaMedic Reefdoser pumps.

I have the lines plumbed into the returns of my cannisters using a type of T in the cannister hose with a 4/6mm inlet (Meerwasser Shop aquaPro2000).

Pumps have varying flow rates depending on the make and model. Some have flow rates that can be set, others have a fixed flow rate of x ml per minute. The dosing is simple. Just mix up a batch of macros and micros that will give you whatever mg/l dose you want into the tank. For example, if you're currently dosing 30mg/l of NO3 into your tank a week, just mix up a batch of KNO3 that will dose about 4.3mg/l a day. Or you can break it down further and dose several times a day if you want.

I've been using a couple of those cheap TOM AquaLifter AW 20 pumps on a timer to dose my 180g tank with macros/micros in seperate 1gal jugs. It works very well for keeping things very constant. This is not true EI dosing, where macros and micros are dosed on opposite days, but I am dosing half EI amounts every day both macros and micros.

It's no overkill to dose daily; if you currently dose let's say 10mg/l of NO3 every two days, just dose 5mg/l every day instead.

There is no requirement for EI dosing to be every other day alternating macros and micros... in fact, nutrient levels will be more consistent with daily dosing.

As to whether the AquaMedic dosing pumps can be set for every other day, I'm not sure. I haven't programmed mine since the original setup and will have to try to dig up the manual .

Some of the digital timers you can buy will allow you to program them to run on specific days of the week. The one I have has an option for Mon, Wed, Fri. I suppose if I used another one and offset the date on it one day I could achieve the opposite days setup. However that requires two timers as opposed to just having both my dosing pumps plugged into the same timer. This saves a couple bucks since those fancy digital timers start at about $20 and go up in price from there.

When automating my tank I was trying to use as few components as possible with the thinking that the fewer items I used the few things there were to fail in the system.

And there is always keeping the wife happy, who was getting a little irritated by the amount of money I was spending to automate..

dapellegrini;15455 said:

With the Reefdoser, can you set it up to run every other day? I was looking at that but it seems like serious over kill to drop one dose per day into my tank. The precision would be nice though. I wish I could program by dose quantity instead of time... Say drop 5ml of this solution in Mon,Wed,Fri - 5ml of this other solution Tues, Thur,Sat....

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The AquaMedic Reefdoser uses the concept of cycle time and on-time. The cycle time is the duration of whatever repeat interval you want. So if you want to dose every other day your cycle time would be 48 hrs. The on-time, of course, is the duration of the dosing period. It does not does by volume; you need to calibrate the dosing time to the volume. So you test it to figure out how long it needs to run to dose, say 5ml, and that becomes your on-time. Let's say that's 1 minute. If you want to does 5ml every other day, you set a cycle time of 48 hrs and an on-time of 1 min.

With the Reefdoser, your cycle time can range from 1 minute to 99hr 59min. The on-time can be as brief as 1 second.

I have one of these and this info is from the manual. I haven't actually set up and programmed mine, although I hope to shortly.

I use the Aquamedic 4 head dose pump. I use 2 heads per tank. 1 head doses from reservoir of KNO3 and KH2PO4 for macro dosing. My primary tank is a 55. I mix 1.75 tsp KNO3 and .5 tsp KH2PO4 per 3qts of water in macro reservoir. I installed a small powerhead in reservoir that runs on a timer that comes on 30 minutes prior to dosing event and runs 1 hour to insure proper mixing and consistency. Macro head cycles daily for 8 minutes and 20 seconds and consistently delivers 1 cup of solution to water column, keeping NO3 at 15-20ppm and PO4 at .5-1.0ppm without fail. I intend to move to a larger reservoir and further dillute solution so I can add slightly more volume to tank to compensate for evaporation. Second head doses micros. I pull undilluted Seachem Flourish (todays macro cycle just initiated as I'm typing, nice) from one reservoir and undilluted Seachem Iron from a second reservoir. I initially mixed Flourish and Fe dilluted with water in a bucket and in less than 2 weeks a nasty rust colored sludge was overtaking the bucket and clogging things up. The two micro reservoir pick ups are t'd together and mixed just a few inches from intake of pump. Each solution is metered through its own hydraulic flow control needle valve. The solution mixes very accurately at a ratio of 1.3 to 1.0 up to 1.7 to 1.0 with a goal mixing ratio of 1.43 to 1.0. I never see a dose stray in quantity by more than .5 grams. A deviation of more than .2 grams happens about 2 out of 5 cycles and is always to the positive side of dosing goal. This head cycles for 15 seconds daily.
All this being said I must say it was quite alot of work over a significant period of time to get this system right. Mostly because I designed and engineered everything other than the dose pump from scratch and there was alot of trial and error in learning what works and what does not and why. There was also a great deal of time and energy spent monitoring dosing to be sure cycles were consistent and accurate. I estimate I spent in time and energy the equivalent of 2+ years of daily dosing by hand to get the automated dosing functioning with precision and repeatability. I am now able to set these systems up in thier entirety in about 10 hours not counting fab time for reservoirs, racks, etc. There is then an additional daily monitoring of reservoir depletion and water column parameters of at least 1 week but ususally 2 weeks to have valves and cycles tuned in properly for the particular tank. Beyond all this there is the expense of components to be accounted for. When money is no problem I use Grundfos batch dosing pumps used in process systems to dose each fert. individually. These pumps are a dream. The accuracy of each batch reads out to .001 ml. They use VFD motors to operate a diaphragm pump. Simply enter dose qauntity for batch and trigger cycle events with pulse input from a seperate timer or other switch mechanism. These pumps cost $1100.00 to $1500.00 each.

vidiots;15565 said:

I've been using a couple of those cheap TOM AquaLifter AW 20 pumps on a timer to dose my 180g tank with macros/micros in seperate 1gal jugs. It works very well for keeping things very constant. This is not true EI dosing, where macros and micros are dosed on opposite days, but I am dosing half EI amounts every day both macros and micros.

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So the Tom AL is working good for you? Good, I have 4 of them waiting to autodose on two tanks. Did you have any problems with them so far? I know they arent as precise as a fancy peristaltic pump but at about 1/10th the price they seemed to be a good alternative . And I thought the whole idea behind EI is that you dont have to be precise, as long as you dosing enough.

Let me see, the AL is rated 3.5G/hr. I'll have to measure the actual flow rate since head loss will reduce this I assume. But my setup will be next to a sump so assuming I get 3g/hr that would translate into a .189L dose (1 minute run time). Would a half EI dose (since will be doing daily) for a 250G tank be to concentrated in about .2L or is this concentration ok? With that concentration and a couple gallon tank I could get several weeks worth of ferts before needing to refill. Is there a recomended concentration? Sorry, I've always dosed dry.

Crazy Loaches;15581 said:

So the Tom AL is working good for you? Good, I have 4 of them waiting to autodose on two tanks. Did you have any problems with them so far? I know they arent as precise as a fancy peristaltic pump but at about 1/10th the price they seemed to be a good alternative . And I thought the whole idea behind EI is that you dont have to be precise, as long as you dosing enough.

Let me see, the AL is rated 3.5G/hr. I'll have to measure the actual flow rate since head loss will reduce this I assume. But my setup will be next to a sump so assuming I get 3g/hr that would translate into a .189L dose (1 minute run time). Would a half EI dose (since will be doing daily) for a 250G tank be to concentrated in about .2L or is this concentration ok? With that concentration and a couple gallon tank I could get several weeks worth of ferts before needing to refill. Is there a recomended concentration? Sorry, I've always dosed dry.

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That is a good ball park figure to start with, but you'll have to time it in place and all setup to get the actual volume dosed over time. The run time can be varried depending on how much water you mix with the ferts, more water = longer run time.

For example mine pumps 1 gallon of water in a little over two weeks at being on for 2 minutes per day. I just mix 2 weeks worth of ferts with the gallon of water every 2 weeks using old milk jugs sitting on the floor next to my sump with the pump sitting ontop of the sump. To calibrate it all you need is a known volume and a stop watch.

So then you havent had any issues with the Aqualifter? If not, I cant see how folks pay so much for the expensive pumps when the Aqualifter is $10. Perhaps the pump being cheaper made wont last as long? I cant see the dosage varying enough once calibrated to cause any issues with EI, but I havent used them yet to see for myself.

Well I'm comming up on a year now since I started using the cheap TOM AL pumps and they are still working like champs.