Thanks so much for the link to APT Instruments. I have wanted to automate the liquid ferts dosing in my 240 and my 30 cube tank for some time, but the only alternatives seemed to be really expensive dosing pumps ($300+) or the refurbished IV pumps (expensive as well) or the Aqua Medic fixed rate dosing pump, which has too high a flow rate (3 liter/hr) for dosing my micros/macros.
The SP100 pumps are just the ticket. I only dose 2 ml/day in the 30 gallon and that pump in the lowest cycle/min with the 1/32" ID tubing allows me to dose that 2 ml over a period of about 30 minutes, which is great.
That is the problem with automating liquid ferts for smaller planted tanks. Most dosing pumps available are too high flow or just too expensive.
Anyways, I ordered two of the SP100s, with the case and the US power cord. The one for the 240 gallon has larger ID tubing than the other. I should have them next week. Hook each one up to a digi timer and I'm all set.
Thanks again for the link. A low cost, accurate, low volume delivery peristaltic pump. Fantastic!