The fish tank water is excellent for plants. But I wouldn't pay attention to its ppm. Although it does contain npk, it's not the same as bottled hydro nutrients. There are aquaponics setups to grow lettuce from fish waste, which is think is something like 5 -.1 -.1 NPK, but it works more because of the beneficial bacteria in the system than the NPK levels. When you have a lot of good bacteria going, you can get by with less NPK, because the bacteria allow the plant to uptake the nutrients more efficiently. Those bacteria love fish tank water, even if you are still adding chemical nutes.

I would not put the pump on a timer. The roots will follow the flow of the water and continue to grow. The more flow you have, the higher the oxygen content of the water.

The bell pepper is a flowering/fruiting plant, and it will want more phosphorous than the other plants you have going. You might want to consider maintaining two separate systems, one for peppers and tomatoes. Otherwise you end up wasting nutes, because the lettuce and green plants can't use the higher levels of phosphorous.

Thanks for the reply. If it isn't a bad Idea I might just take the gallon or two out of the fish tank scheduled refresh and pour it in the system. I really want to have a second system. I let enought space for it however that means I have to dig another hole for the drum. LoL. (Broke through a layer of lime stone) this way I can like you said not waste nutes.

The down side I see to the fish water is the unknown ppm. Not that there is anything in there that would hurt, you are kinda in a guessing game with the. Unknown ppm. I was doing that with300 ppm tap water. Fought it for weeks and finally I drained and refilled with 3 ppm rain water. Now it is all simple.

On the daming to get the water up to the cubes. I did this at first as well and after fighting stem rot I took the dams out. Now I start the seedlings in a 25.00 ebb and flow setup and don't put them into the nft until the roots are out the bottom of the net cups. The stems are much healthier now.

I just watched your video, your water seems way deep to me. But let me know if that works.

On my gutter system the film of water is 1/8 inch deep or less. Maybe you are doing something there I just am not familiar with.

Since this is my first run at the HPVG i was eager to get my seedlings out of dirt and into some Grodan cubes and into the pipes. The majority of the seedlings took to the pipes even in the 100 degree Texas heat. About the dams in the pipes. I was afraid the roots would dry out so i damned up the water. I have a lot of flow so it didn't hurt the plants however the roots did start to grow out the side of the baskets. I am trying to cut the dept by using the pvc cutouts to just splash the water on the bottom of the baskets like a speed bump rather than flood it. Thanks again for all the posts.

I hope once i have the system up and running i can set up a smaller pipe to feed the seedlings or just a different set up. My initial thought was to drill the last 2" or 3" drain pipe and put small pots in it ..... but i think the nutrient will be to much... Thoughts???

Hey, I am far from knowing everything if it is working I say do it. More I thought about it you kinda have a shallow water recirculating system. As long as you have an air space might work ok. Good luck!

Since this is my first run at the HPVG i was eager to get my seedlings out of dirt and into some Grodan cubes and into the pipes. The majority of the seedlings took to the pipes even in the 100 degree Texas heat. About the dams in the pipes. I was afraid the roots would dry out so i damned up the water. I have a lot of flow so it didn't hurt the plants however the roots did start to grow out the side of the baskets. I am trying to cut the dept by using the pvc cutouts to just splash the water on the bottom of the baskets like a speed bump rather than flood it. Thanks again for all the posts.

I hope once i have the system up and running i can set up a smaller pipe to feed the seedlings or just a different set up. My initial thought was to drill the last 2" or 3" drain pipe and put small pots in it ..... but i think the nutrient will be to much... Thoughts???