New member with questions

[Glenn Thompson]

Hello, My name is Glenn Thompson and I'm located in Thousand Oaks CA. About 50 miles north of

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I'm looking forward to many conversations with the group, because I'm a newbie with Aquaponics gardening a need some advice.

I hope this is the forum that I can give you some back ground on my system and receive advise that is much needed.

Here I go, 

I constructed a 20' wide x 24' long radius top greenhouse in my back yard.  The roof height is close to 9' high in the center.  The entire greenhouse is covered with 6 mill plastic.  I have installed two automatic solar vents in the ceiling along with one door access to enter the green house.  I installed a 24" suction fan system with two auto lifting louver doors to draw fresh air when needed.

I installed five 110 gal. tubs that hold my Tilapia fish and are plumbed at the exact level so all will maintain the same level. I also have constructed a bio filter using two 55 gal. drums plumbed together.  I have placed 3/4" black lava rock in the barrels with a 7" void area at the bottom for flushing when necessary.  The bio filters are plumbed to all five of the tubs that circulate 24/7 by a 1/8 hp, 2400 gph pump. The total amount of water is around 650 gallons.

I have constructed a wood frame system above my tubs and along one side of the green house to hold my grow trays. I have eleven 3'x3'x71/2" deep trays and four 2'x4'x71/2" deep trays.  Along the back wall I hung eight five gallon buckets to hold my vine crops.  All of the trays are plumbed so the draining water will gravity feed back into my tubs.  All of the grow media areas are filled with Hydroton media.

I have another 1/8hp pump that pulls the water from my tubs and fills all the grow trays and buckets.  A timer system controls the water frequency.

I have placed two 55 drums off to one side in the greenhouse for treated water to replenish the tub/fish water.

I have installed a gas heater mounted from the ceiling so I can maintain a set temperature within the greenhouse.

At this time I have around 90 Talipia with a average size of 8".  I started with 130 - 1" fingerlings. 

Now my problems;

I check the water conditions levels about every three days and keep a log.  As the fish have grown it has sometimes been difficult to maintain good levels.  Water changes have helped. The PH has varied from 6 to 8. The Ammonia has has not gone above .25.  The Nitrites have been a steady 0 or .15 at the most. The Nitrate levels have varied the most. Today it is at 5.0 but has been off the color charts many of day. A pure red color.

My vegetables are a constant light green in color not a normal green. The tomato vines grow but little to no production.  Lettuce, broccoli, cauliflower, etc do not grow much once I have transplanted my seedlings to the grow tray media.  They droop and again do not grow.

I planted strawberries in four of my tray which grew petty well but little to no fruit.  It seamed once the strawberry started to ripen they would become soft and rotten.

Pollination is a problem also.

Sorry for the long overview but wanted to give a description of my system to see if that is part off the problem..

Any suggestions?   

Thank you for  your time.

Glenn, 

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[Alex Veidel]

What is the temperature of your water and what is the surrounding temperature in the greenhouse? And how old is your system? Are your tomatoes flowering and there is no fruit? Or are they not flowering at all? On a side note, sounds like you have a cools setup; would love to see some pictures :)

[Glenn Thompson]

Thank you for your response, The present temp in the greenhouse is 60 degrees held by a gas heater.  The water temp is 60 also. The system bio filter has been running since Sept.

The Tomato vines vary. One has only has a couple of flowers. Three others have had lots of flowers but 50% die.  Of the balance I may get five or so tomato's but have a problem with ripening.

Attached are some older pictures. I will take some new shots to get a better idea of the system along with plant problems.

Glenn

Alex Veidel said:

What is the temperature of your water and what is the surrounding temperature in the greenhouse? And how old is your system? Are your tomatoes flowering and there is no fruit? Or are they not flowering at all? On a side note, sounds like you have a cools setup; would love to see some pictures

[Glenn Thompson]

Additional pictures
Glenn Thompson said:

Thank you for your response, The present temp in the greenhouse is 60 degrees held by a gas heater.  The water temp is 60 also. The system bio filter has been running since Sept.

The Tomato vines vary. One has only has a couple of flowers. Three others have had lots of flowers but 50% die.  Of the balance I may get five or so tomato's but have a problem with ripening.

Attached are some older pictures. I will take some new shots to get a better idea of the system along with plant problems.

Glenn

Alex Veidel said:

What is the temperature of your water and what is the surrounding temperature in the greenhouse? And how old is your system? Are your tomatoes flowering and there is no fruit? Or are they not flowering at all? On a side note, sounds like you have a cools setup; would love to see some pictures

[Vlad Jovanovic]

Hi Glenn, judging from your pictures and your description two things stand out...

1) It seems you have a transpiration/moisture problem that has lead to fungal issues...downy mildew/powdery mildew and likely, phytopthoria. As much as it may pain you to lose some of that heat, ventilation and air movement is paramount. Gas heaters add a lot of extra moisture unfortunately. Those plants look really badly infected.

2) Potassium (K) and likely a bit of magnesium (Mg) deficiency. Tom's will take forever to ripen, or not ripen at all...actually they may not even form fruit at all without adequate levels of K. Your pics also indicate that a bit of K may be lacking.

Things like broccoli or cauliflower (and most all common cultivars in the brassica family) need quite a bit of Mg to grow well...and of course K too. It might really, really help to prune those toms down to one (maybe two) fruiting branches. Prune all axial leaf suckers, and all fruiting branch suckers. Having an un-ruly mess of spindly weak vines only exacerbates both fungal, as well as nutrient issues. Prune all those infected and dead leaves/branches as well, as by this point they are spore factories working overtime. Spray whatever vegetation is left with some potassium bicarbonate (KHCO3) or even sodium bicarbonate (NaHCO3) to create an inhospitable environment (pH) for the various fungi to spread.

As far as the K issues...if you want to address that in an immediate and fish safe (actually more than just fish safe...fish beneficial) way, salt your system with potassium chloride (KCl) to the tune of 0.250 ppt (250ppm).

Good luck.

[Jeffrey Ihara]

Just a thought. Glenn indicated that pH fluctuated between 6-8. Is this normal? Isn't that tough on both the fish and the plants? Based on my experience (in soil) I'd think that pH8 would be problematic for nutrient uptake. If high pH is causing nute lockout, then adding bicarbonate would tend to make things stay on the high side.

I'm in southern Cal as well, and my cucurbits are always hit by powdery mildew as soon as things get a bit cooler--so with your greenhouse running at 60°F max and on only wintertime insolation I'd be awestruck if you didn't have it. Summer veggies like a lot of sun and heat. With the exception of leaf color, your tomatoes look pretty much like my leftover vines did outside (before I took them out yesterday). Unless you're willing to simulate summertime conditions during winter months, it might be a good idea to transition over to cooler-weather crops that will be happy with 60°F.

[Vlad Jovanovic]

If by "the pH has varied from 6 to 8" Glenn means that he is experiencing a diurnal shift of 2 pH units, he should take care of that by blocking out any excess light that may be hitting his water. That should go a ways in taking care of the algae which causes such diurnal pH swings. Such swings probably are pretty tough on the fish, but in reality I doubt the plants care much. Which is not to say that a nice low plant loving and stable pH isn't a good thing, just that it's probably not what is at the root of Glenn's problems. 

Foliar spraying a bicarbonate fungicide isn't going to effect system water pH much if at all.

Jeffery is right, 60 degrees pretty much sucks for growing tomatoes, but is really great for mildew and various fungal pathogens. Short of a "massive" investment on more heat and light, there's really not much one can do on that front. There is a reason why tomatoes taste like a wet sponge and cost as much as they do in January. If they were that simple and cheap to grow (well) in the winter...any 'ol producer would be doing it. 

These deficiencies in temp and light, can somewhat (key word being somewhat) be mitigated by increasing nutrient levels, and is the cheapest out of the three (light, heat, nutrients) to add. Really though, Jeffery hit the nail on the head...Stick to cool weather crops in the winter time, or prepare to invest in creating summertime conditions for summertime-like production. Anything else is pretty much illusory.

It doesn't look like pH related nutrient lockouts are really the culprits here. New-ish AP systems seem to be notoriously lacking in K (by their nature, and depending on what NH4 source you used to cycle with) and toms are absolute K hogs...and light/sunshine hogs. Damp cool conditions in a GH are usually a fungal nightmare...more ventilation/air movement and fungicides (like fish safe bicarbs of course) are the only ways I know of to deal with this...Again short of massive investments on the environmental control side...

[Jeffrey Ihara]

Sounds like foliar potassium bicarbonate is something for me to try as well. Thanks for the tip!